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Number

16,421

16,421 is a prime, odd.

16,421 (sixteen thousand four hundred twenty-one) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x4025.

Arithmetic Number Chen Prime Cousin Prime Cube-Free Deficient Number Evil Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Sophie Germain Prime Squarefree

Interestingness

Properties

Parity
Odd
Digit count
5
Digit sum
14
Digit product
48
Digital root
5
Palindrome
No
Bit width
15 bits
Reversed
12,461
Recamán's sequence
a(17,870) = 16,421
Square (n²)
269,649,241
Cube (n³)
4,427,910,186,461
Divisor count
2
σ(n) — sum of divisors
16,422
φ(n) — Euler's totient
16,420

Primality

16,421 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 16421
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 16,421)
1 × 16421
First multiples
16,421 · 32,842 (double) · 49,263 · 65,684 · 82,105 · 98,526 · 114,947 · 131,368 · 147,789 · 164,210

Sums & aliquot sequence

As a sum of two squares: 86² + 95²
As consecutive integers: 8,210 + 8,211

Continued fraction of √n

√16,421 = [128; (6, 1, 11, 1, 22, 2, 1, 1, 1, 8, 4, 1, 2, 1, 1, 3, 5, 5, 1, 3, 2, 1, 3, 13, …)]

Representations

In words
sixteen thousand four hundred twenty-one
Ordinal
16421st
Binary
100000000100101
Octal
40045
Hexadecimal
0x4025
Base64
QCU=
One's complement
49,114 (16-bit)
Scientific notation
1.6421 × 10⁴
As a duration
16,421 s = 4 hours, 33 minutes, 41 seconds
In other bases
ternary (3) 211112012
quaternary (4) 10000211
quinary (5) 1011141
senary (6) 204005
septenary (7) 65606
nonary (9) 24465
undecimal (11) 11379
duodecimal (12) 9605
tridecimal (13) 7622
tetradecimal (14) 5dad
pentadecimal (15) 4ceb

As an angle

16,421° = 45 × 360° + 221°
221° ≈ 3.857 rad
Compass bearing: SW (southwest)

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓏺
Greek (Milesian)
͵ιϛυκαʹ
Mayan (base 20)
𝋢·𝋡·𝋡·𝋡
Chinese
一萬六千四百二十一
Chinese (financial)
壹萬陸仟肆佰貳拾壹
In other modern scripts
Eastern Arabic ١٦٤٢١ Devanagari १६४२१ Bengali ১৬৪২১ Tamil ௧௬௪௨௧ Thai ๑๖๔๒๑ Tibetan ༡༦༤༢༡ Khmer ១៦៤២១ Lao ໑໖໔໒໑ Burmese ၁၆၄၂၁

Digit at this position in famous constants

π — Pi (π)
Digit 16,421 = 6
e — Euler's number (e)
Digit 16,421 = 2
φ — Golden ratio (φ)
Digit 16,421 = 0
√2 — Pythagoras's (√2)
Digit 16,421 = 4
ln 2 — Natural log of 2
Digit 16,421 = 1
γ — Euler-Mascheroni (γ)
Digit 16,421 = 2

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 16,417 (gap of 4)
  • Next prime: 16,427 (gap of 6)

Pair status: cousin with 16417, sexy with 16427.

Unicode codepoint
CJK Unified Ideograph-4025
U+4025
Other letter (Lo)

UTF-8 encoding: E4 80 A5 (3 bytes).

Hex color
#004025
RGB(0, 64, 37)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.64.37.

Address
0.0.64.37
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.64.37

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Musical pitch

Heard as a frequency, 16,421 Hz is closest to:

  • Concert pitch (A4 = 440 Hz): C10 (16744 Hz, -34¢)
  • Scientific pitch (C4 = 256 Hz): C10 (16384 Hz, +4¢)
  • Baroque pitch (A4 = 415 Hz): C♯10 (16731.8 Hz, -32¢)
Position in π

The digit sequence 16421 first appears in π at position 7,602 of the decimal expansion (the 7,602ordinal-suffix:nd digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Related reading

  • Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
  • Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.