66513664 has 36 divisors (see below), whose sum is σ = 151738384. Its totient is φ = 28505088.

The previous prime is 66513641. The next prime is 66513703. The reversal of 66513664 is 46631566.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16767 + ... + 20350.

Almost surely, 2^66513664 is an apocalyptic number.

66513664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66513664 is an abundant number, since it is smaller than the sum of its proper divisors (85224720).

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

66513664 is an equidigital number, since it uses as much as digits as its factorization.

66513664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37140 (or 37126 counting only the distinct ones).

The product of its digits is 77760, while the sum is 37.

The square root of 66513664 is about 8155.5909657118. The cubic root of 66513664 is about 405.1696977216.

The spelling of 66513664 in words is "sixty-six million, five hundred thirteen thousand, six hundred sixty-four".