66663688 has 32 divisors (see below), whose sum is σ = 153840960. Its totient is φ = 26372160.

The previous prime is 66663661. The next prime is 66663689. The reversal of 66663688 is 88636666.

66663688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66663688² = 8888094595522688, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66663689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45058 + ... + 46513.

It is an arithmetic number, because the mean of its divisors is an integer number (4807530).

Almost surely, 2^66663688 is an apocalyptic number.

It is an amenable number.

66663688 is an abundant number, since it is smaller than the sum of its proper divisors (87177272).

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

66663688 is a wasteful number, since it uses less digits than its factorization.

66663688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91597 (or 91593 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 49.

The square root of 66663688 is about 8164.7834019036. The cubic root of 66663688 is about 405.4740939975.

The spelling of 66663688 in words is "sixty-six million, six hundred sixty-three thousand, six hundred eighty-eight".