21515425160664 has 64 divisors (see below), whose sum is σ = 54045228314880. Its totient is φ = 7137588528000.

The previous prime is 21515425160659. The next prime is 21515425160759. The reversal of 21515425160664 is 46606152451512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 239892549 + ... + 239982219.

It is an arithmetic number, because the mean of its divisors is an integer number (844456692420).

Almost surely, 2^{21515425160664} is an apocalyptic number.

21515425160664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21515425160664 is an abundant number, since it is smaller than the sum of its proper divisors (32529803154216).

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

21515425160664 is a wasteful number, since it uses less digits than its factorization.

21515425160664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137272 (or 137268 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 48.

The spelling of 21515425160664 in words is "twenty-one trillion, five hundred fifteen billion, four hundred twenty-five million, one hundred sixty thousand, six hundred sixty-four".