21915035964 has 72 divisors (see below), whose sum is σ = 57215034240. Its totient is φ = 7065446400.

The previous prime is 21915035893. The next prime is 21915035969. The reversal of 21915035964 is 46953051912.

21915035964 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 50 + 3 + 596 + 4 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21915035969) 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, 2541292 + ... + 2549900.

Almost surely, 2^21915035964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21915035964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28607517120).

21915035964 is an abundant number, since it is smaller than the sum of its proper divisors (35299998276).

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

21915035964 is a wasteful number, since it uses less digits than its factorization.

21915035964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10931 (or 10926 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 45.

The spelling of 21915035964 in words is "twenty-one billion, nine hundred fifteen million, thirty-five thousand, nine hundred sixty-four".