66640756 has 36 divisors (see below), whose sum is σ = 144332832. Its totient is φ = 26361504.

The previous prime is 66640727. The next prime is 66640759. The reversal of 66640756 is 65704666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66640759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2310 + ... + 11773.

Almost surely, 2^66640756 is an apocalyptic number.

It is an amenable number.

66640756 is an abundant number, since it is smaller than the sum of its proper divisors (77692076).

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

66640756 is a wasteful number, since it uses less digits than its factorization.

66640756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14120 (or 14105 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 66640756 is about 8163.3789572701. The cubic root of 66640756 is about 405.4275949283.

The spelling of 66640756 in words is "sixty-six million, six hundred forty thousand, seven hundred fifty-six".