21474670251 has 16 divisors (see below), whose sum is σ = 29062748160. Its totient is φ = 14102362560.

The previous prime is 21474670193. The next prime is 21474670253. The reversal of 21474670251 is 15207647412.

It is not a de Polignac number, because 21474670251 - 2⁷ = 21474670123 is a prime.

It is a super-2 number, since 2×21474670251² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21474670253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2970 + ... + 207263.

It is an arithmetic number, because the mean of its divisors is an integer number (1816421760).

Almost surely, 2^21474670251 is an apocalyptic number.

21474670251 is a deficient number, since it is larger than the sum of its proper divisors (7588077909).

21474670251 is a wasteful number, since it uses less digits than its factorization.

21474670251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210746.

The product of its (nonzero) digits is 94080, while the sum is 39.

The spelling of 21474670251 in words is "twenty-one billion, four hundred seventy-four million, six hundred seventy thousand, two hundred fifty-one".