21285868952 has 8 divisors (see below), whose sum is σ = 39911004300. Its totient is φ = 10642934472.

The previous prime is 21285868943. The next prime is 21285868973. The reversal of 21285868952 is 25986858212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330366802 + ... + 1330366817.

Almost surely, 2^21285868952 is an apocalyptic number.

It is an amenable number.

21285868952 is a deficient number, since it is larger than the sum of its proper divisors (18625135348).

21285868952 is a wasteful number, since it uses less digits than its factorization.

21285868952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660733625 (or 2660733621 counting only the distinct ones).

The product of its digits is 5529600, while the sum is 56.

The spelling of 21285868952 in words is "twenty-one billion, two hundred eighty-five million, eight hundred sixty-eight thousand, nine hundred fifty-two".