21531085588 has 48 divisors (see below), whose sum is σ = 41449734144. Its totient is φ = 9753210720.

The previous prime is 21531085579. The next prime is 21531085591. The reversal of 21531085588 is 88558013512.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53731 + ... + 214357.

It is an arithmetic number, because the mean of its divisors is an integer number (863536128).

Almost surely, 2^21531085588 is an apocalyptic number.

It is an amenable number.

21531085588 is a deficient number, since it is larger than the sum of its proper divisors (19918648556).

21531085588 is a wasteful number, since it uses less digits than its factorization.

21531085588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160732 (or 160730 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 46.

The spelling of 21531085588 in words is "twenty-one billion, five hundred thirty-one million, eighty-five thousand, five hundred eighty-eight".