21861311604 has 48 divisors (see below), whose sum is σ = 55671973056. Its totient is φ = 6621664000.

The previous prime is 21861311567. The next prime is 21861311627. The reversal of 21861311604 is 40611316812.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 267154 + ... + 339254.

It is an arithmetic number, because the mean of its divisors is an integer number (1159832772).

Almost surely, 2^21861311604 is an apocalyptic number.

It is an amenable number.

21861311604 is an abundant number, since it is smaller than the sum of its proper divisors (33810661452).

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

21861311604 is a wasteful number, since it uses less digits than its factorization.

21861311604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74416 (or 74414 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The spelling of 21861311604 in words is "twenty-one billion, eight hundred sixty-one million, three hundred eleven thousand, six hundred four".