666749238 has 32 divisors (see below), whose sum is σ = 1372667904. Its totient is φ = 215796672.

The previous prime is 666749201. The next prime is 666749243. The reversal of 666749238 is 832947666.

It is a happy number.

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, 26506 + ... + 45122.

It is an arithmetic number, because the mean of its divisors is an integer number (42895872).

Almost surely, 2^666749238 is an apocalyptic number.

666749238 is an abundant number, since it is smaller than the sum of its proper divisors (705918666).

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

666749238 is a wasteful number, since it uses less digits than its factorization.

666749238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18796.

The product of its digits is 2612736, while the sum is 51.

The square root of 666749238 is about 25821.4879122021. The cubic root of 666749238 is about 873.6165295993.

The spelling of 666749238 in words is "six hundred sixty-six million, seven hundred forty-nine thousand, two hundred thirty-eight".