21521887732 has 24 divisors (see below), whose sum is σ = 39989920320. Its totient is φ = 10099724160.

The previous prime is 21521887721. The next prime is 21521887757. The reversal of 21521887732 is 23778812512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 416394 + ... + 465217.

It is an arithmetic number, because the mean of its divisors is an integer number (1666246680).

Almost surely, 2^21521887732 is an apocalyptic number.

It is an amenable number.

21521887732 is a deficient number, since it is larger than the sum of its proper divisors (18468032588).

21521887732 is a wasteful number, since it uses less digits than its factorization.

21521887732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881991 (or 881989 counting only the distinct ones).

The product of its digits is 376320, while the sum is 46.

The spelling of 21521887732 in words is "twenty-one billion, five hundred twenty-one million, eight hundred eighty-seven thousand, seven hundred thirty-two".