21663656032 has 24 divisors (see below), whose sum is σ = 43164187416. Its totient is φ = 10701322752.

The previous prime is 21663656017. The next prime is 21663656033. The reversal of 21663656032 is 23065636612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21663656033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4075593 + ... + 4080904.

It is an arithmetic number, because the mean of its divisors is an integer number (1798507809).

Almost surely, 2^21663656032 is an apocalyptic number.

It is an amenable number.

21663656032 is a deficient number, since it is larger than the sum of its proper divisors (21500531384).

21663656032 is an equidigital number, since it uses as much as digits as its factorization.

21663656032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8156590 (or 8156582 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

The spelling of 21663656032 in words is "twenty-one billion, six hundred sixty-three million, six hundred fifty-six thousand, thirty-two".