21495775764 has 24 divisors (see below), whose sum is σ = 50197855680. Its totient is φ = 7159394944.

The previous prime is 21495775759. The next prime is 21495775831. The reversal of 21495775764 is 46757759412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 717669 + ... + 747020.

It is an arithmetic number, because the mean of its divisors is an integer number (2091577320).

Almost surely, 2^21495775764 is an apocalyptic number.

It is an amenable number.

21495775764 is an abundant number, since it is smaller than the sum of its proper divisors (28702079916).

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

21495775764 is a wasteful number, since it uses less digits than its factorization.

21495775764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1465919 (or 1465917 counting only the distinct ones).

The product of its digits is 14817600, while the sum is 57.

The spelling of 21495775764 in words is "twenty-one billion, four hundred ninety-five million, seven hundred seventy-five thousand, seven hundred sixty-four".