66509568 has 54 divisors (see below), whose sum is σ = 191770124. Its totient is φ = 22169088.

The previous prime is 66509563. The next prime is 66509603. The reversal of 66509568 is 86590566.

It is not an unprimeable number, because it can be changed into a prime (66509561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12130 + ... + 16737.

Almost surely, 2^66509568 is an apocalyptic number.

It is an amenable number.

66509568 is an abundant number, since it is smaller than the sum of its proper divisors (125260556).

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

66509568 is a wasteful number, since it uses less digits than its factorization.

66509568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28889 (or 28872 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 66509568 is about 8155.3398457698. The cubic root of 66509568 is about 405.1613805877.

The spelling of 66509568 in words is "sixty-six million, five hundred nine thousand, five hundred sixty-eight".