21023402136 has 64 divisors (see below), whose sum is σ = 57386689920. Its totient is φ = 6365157120.

The previous prime is 21023402119. The next prime is 21023402137. The reversal of 21023402136 is 63120432012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023402137) 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, 272796 + ... + 341268.

It is an arithmetic number, because the mean of its divisors is an integer number (896667030).

Almost surely, 2^21023402136 is an apocalyptic number.

It is an amenable number.

21023402136 is an abundant number, since it is smaller than the sum of its proper divisors (36363287784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21023402136 is a wasteful number, since it uses less digits than its factorization.

21023402136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69656 (or 69652 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21023402136 its reverse (63120432012), we get a palindrome (84143834148).

The spelling of 21023402136 in words is "twenty-one billion, twenty-three million, four hundred two thousand, one hundred thirty-six".