66138670 has 32 divisors (see below), whose sum is σ = 135753408. Its totient is φ = 22983168.

The previous prime is 66138661. The next prime is 66138697. The reversal of 66138670 is 7683166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12754 + ... + 17173.

It is an arithmetic number, because the mean of its divisors is an integer number (4242294).

Almost surely, 2^66138670 is an apocalyptic number.

66138670 is an abundant number, since it is smaller than the sum of its proper divisors (69614738).

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

66138670 is a wasteful number, since it uses less digits than its factorization.

66138670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29964.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 66138670 is about 8132.5684749653. The cubic root of 66138670 is about 404.4068337460.

The spelling of 66138670 in words is "sixty-six million, one hundred thirty-eight thousand, six hundred seventy".