21756032656 has 40 divisors (see below), whose sum is σ = 42620709600. Its totient is φ = 10757497344.

The previous prime is 21756032611. The next prime is 21756032657. The reversal of 21756032656 is 65623065712.

It is not an unprimeable number, because it can be changed into a prime (21756032657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 994120 + ... + 1015768.

It is an arithmetic number, because the mean of its divisors is an integer number (1065517740).

Almost surely, 2^21756032656 is an apocalyptic number.

It is an amenable number.

21756032656 is a deficient number, since it is larger than the sum of its proper divisors (20864676944).

21756032656 is a wasteful number, since it uses less digits than its factorization.

21756032656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22351 (or 22345 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 21756032656 in words is "twenty-one billion, seven hundred fifty-six million, thirty-two thousand, six hundred fifty-six".