21399608008 has 16 divisors (see below), whose sum is σ = 41208705180. Its totient is φ = 10410619968.

The previous prime is 21399608003. The next prime is 21399608033. The reversal of 21399608008 is 80080699312.

It can be written as a sum of positive squares in 2 ways, for example, as 15544603684 + 5855004324 = 124678^2 + 76518^2 .

It is not an unprimeable number, because it can be changed into a prime (21399608003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36147691 + ... + 36148282.

Almost surely, 2^21399608008 is an apocalyptic number.

It is an amenable number.

21399608008 is a deficient number, since it is larger than the sum of its proper divisors (19809097172).

21399608008 is a wasteful number, since it uses less digits than its factorization.

21399608008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72296016 (or 72296012 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 46.

The spelling of 21399608008 in words is "twenty-one billion, three hundred ninety-nine million, six hundred eight thousand, eight".