70 (number)

← 69 70 71 →
Cardinalseventy
Ordinal70th
(seventieth)
Factorization2 × 5 × 7
Greek numeralΟ´
Roman numeralLXX
Binary10001102
Ternary21213
Quaternary10124
Quinary2405
Senary1546
Octal1068
Duodecimal5A12
Hexadecimal4616
Vigesimal3A20
Base 361Y36

Seventy is the natural number that comes after sixty-nine and before seventy-one.

The prime factors of seventy are 2, 5, and 7. (2 * 5 * 7 = 70)

In mathematics

70 is a pentagonal number, a Pell number, and a central binomial coefficient.

70 is the smallest weird number, because it is an abundant number but it is not semiperfect.

References

  1. 1 2 3 Vanovschi, Vitalii. "Properties of the number 70". www.numberempire.com. Retrieved 2026-09-27.
  2. ↑ Weisstein, Eric W. "Pell Number". mathworld.wolfram.com. Wolfram Research, Inc. Retrieved 2026-09-27.
  3. ↑ Sloane, N. J. A. (ed.). "Sequence A000984 (Central binomial coefficients: binomial(2*n,n) as (2*n)!/(n!)^2.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  4. ↑ Weisstein, Eric W. "Weird Number". mathworld.wolfram.com. Wolfram Research, Inc. Retrieved 2026-09-27.