21612925961 has 48 divisors (see below), whose sum is σ = 26186587200. Its totient is φ = 17661974400.

The previous prime is 21612925951. The next prime is 21612925963. The reversal of 21612925961 is 16952921612.

It is not a de Polignac number, because 21612925961 - 2²² = 21608731657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21612925963) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6792791 + ... + 6795971.

It is an arithmetic number, because the mean of its divisors is an integer number (545553900).

Almost surely, 2^21612925961 is an apocalyptic number.

It is an amenable number.

21612925961 is a deficient number, since it is larger than the sum of its proper divisors (4573661239).

21612925961 is a wasteful number, since it uses less digits than its factorization.

21612925961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3318 (or 3299 counting only the distinct ones).

The product of its digits is 116640, while the sum is 44.

The spelling of 21612925961 in words is "twenty-one billion, six hundred twelve million, nine hundred twenty-five thousand, nine hundred sixty-one".