21509090512 has 40 divisors (see below), whose sum is σ = 51290911616. Its totient is φ = 8509090176.

The previous prime is 21509090509. The next prime is 21509090531.

21509090512 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7384908 + ... + 7387819.

Almost surely, 2^21509090512 is an apocalyptic number.

It is an amenable number.

21509090512 is an abundant number, since it is smaller than the sum of its proper divisors (29781821104).

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

21509090512 is a wasteful number, since it uses less digits than its factorization.

21509090512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14772755 (or 14772749 counting only the distinct ones).

The product of its (nonzero) digits is 8100, while the sum is 34.

The spelling of 21509090512 in words is "twenty-one billion, five hundred nine million, ninety thousand, five hundred twelve".