66139660 has 24 divisors (see below), whose sum is σ = 139131216. Its totient is φ = 26410560.

The previous prime is 66139657. The next prime is 66139663. The reversal of 66139660 is 6693166.

66139660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66139657) and next prime (66139663).

It is not an unprimeable number, because it can be changed into a prime (66139663) 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, 10719 + ... + 15721.

It is an arithmetic number, because the mean of its divisors is an integer number (5797134).

Almost surely, 2^66139660 is an apocalyptic number.

It is an amenable number.

66139660 is an abundant number, since it is smaller than the sum of its proper divisors (72991556).

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

66139660 is a wasteful number, since it uses less digits than its factorization.

66139660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5673 (or 5671 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 66139660 is about 8132.6293411172. The cubic root of 66139660 is about 404.4088515306.

The spelling of 66139660 in words is "sixty-six million, one hundred thirty-nine thousand, six hundred sixty".