21957087723 has 16 divisors (see below), whose sum is σ = 29406551040. Its totient is φ = 14572906496.

The previous prime is 21957087671. The next prime is 21957087769. The reversal of 21957087723 is 32778075912.

It is a cyclic number.

It is not a de Polignac number, because 21957087723 - 2²² = 21952893419 is a prime.

It is a super-2 number, since 2×21957087723² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21957187723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1565086 + ... + 1579052.

It is an arithmetic number, because the mean of its divisors is an integer number (1837909440).

Almost surely, 2^21957087723 is an apocalyptic number.

21957087723 is a deficient number, since it is larger than the sum of its proper divisors (7449463317).

21957087723 is a wasteful number, since it uses less digits than its factorization.

21957087723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16266.

The product of its (nonzero) digits is 1481760, while the sum is 51.

The spelling of 21957087723 in words is "twenty-one billion, nine hundred fifty-seven million, eighty-seven thousand, seven hundred twenty-three".