21163145025656 has 32 divisors (see below), whose sum is σ = 39742451226000. Its totient is φ = 10565166272256.

The previous prime is 21163145025611. The next prime is 21163145025689. The reversal of 21163145025656 is 65652054136112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21163145025656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20113250 + ... + 21139278.

Almost surely, 2^{21163145025656} is an apocalyptic number.

It is an amenable number.

21163145025656 is a deficient number, since it is larger than the sum of its proper divisors (18579306200344).

21163145025656 is a wasteful number, since it uses less digits than its factorization.

21163145025656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030031 (or 1030027 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21163145025656 in words is "twenty-one trillion, one hundred sixty-three billion, one hundred forty-five million, twenty-five thousand, six hundred fifty-six".