21515413512 has 16 divisors (see below), whose sum is σ = 53788533840. Its totient is φ = 7171804496.

The previous prime is 21515413501. The next prime is 21515413523. The reversal of 21515413512 is 21531451512.

It is an interprime number because it is at equal distance from previous prime (21515413501) and next prime (21515413523).

It is a self number, because there is not a number n which added to its sum of digits gives 21515413512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 448237758 + ... + 448237805.

It is an arithmetic number, because the mean of its divisors is an integer number (3361783365).

Almost surely, 2^21515413512 is an apocalyptic number.

It is an amenable number.

21515413512 is an abundant number, since it is smaller than the sum of its proper divisors (32273120328).

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

21515413512 is a wasteful number, since it uses less digits than its factorization.

21515413512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 896475572 (or 896475568 counting only the distinct ones).

The product of its digits is 6000, while the sum is 30.

The spelling of 21515413512 in words is "twenty-one billion, five hundred fifteen million, four hundred thirteen thousand, five hundred twelve".