21372650931 has 4 divisors (see below), whose sum is σ = 28496867912. Its totient is φ = 14248433952.

The previous prime is 21372650921. The next prime is 21372650941. The reversal of 21372650931 is 13905627312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21372650921) and next prime (21372650941).

It is not a de Polignac number, because 21372650931 - 2¹⁷ = 21372519859 is a prime.

It is a super-2 number, since 2×21372650931² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21372650931.

It is not an unprimeable number, because it can be changed into a prime (21372650911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3562108486 + ... + 3562108491.

It is an arithmetic number, because the mean of its divisors is an integer number (7124216978).

Almost surely, 2^21372650931 is an apocalyptic number.

21372650931 is a deficient number, since it is larger than the sum of its proper divisors (7124216981).

21372650931 is an equidigital number, since it uses as much as digits as its factorization.

21372650931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7124216980.

The product of its (nonzero) digits is 68040, while the sum is 39.

The spelling of 21372650931 in words is "twenty-one billion, three hundred seventy-two million, six hundred fifty thousand, nine hundred thirty-one".