21657942033 has 24 divisors (see below), whose sum is σ = 36175906368. Its totient is φ = 11423968416.

The previous prime is 21657942029. The next prime is 21657942043. The reversal of 21657942033 is 33024975612.

It is not a de Polignac number, because 21657942033 - 2² = 21657942029 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21657942043) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5664741 + ... + 5668562.

It is an arithmetic number, because the mean of its divisors is an integer number (1507329432).

Almost surely, 2^21657942033 is an apocalyptic number.

It is an amenable number.

21657942033 is a deficient number, since it is larger than the sum of its proper divisors (14517964335).

21657942033 is a wasteful number, since it uses less digits than its factorization.

21657942033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11333333 (or 11333326 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 42.

The spelling of 21657942033 in words is "twenty-one billion, six hundred fifty-seven million, nine hundred forty-two thousand, thirty-three".