21513214908 has 36 divisors (see below), whose sum is σ = 54554395168. Its totient is φ = 7148157120.

The previous prime is 21513214897. The next prime is 21513214967. The reversal of 21513214908 is 80941231512.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 943348 + ... + 965883.

Almost surely, 2^21513214908 is an apocalyptic number.

It is an amenable number.

21513214908 is an abundant number, since it is smaller than the sum of its proper divisors (33041180260).

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

21513214908 is a wasteful number, since it uses less digits than its factorization.

21513214908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1909554 (or 1909549 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 21513214908 in words is "twenty-one billion, five hundred thirteen million, two hundred fourteen thousand, nine hundred eight".