666679942 has 16 divisors (see below), whose sum is σ = 1053768240. Its totient is φ = 315461088.

The previous prime is 666679921. The next prime is 666679957. The reversal of 666679942 is 249976666.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 29088 + ... + 46684.

It is an arithmetic number, because the mean of its divisors is an integer number (65860515).

Almost surely, 2^666679942 is an apocalyptic number.

666679942 is a deficient number, since it is larger than the sum of its proper divisors (387088298).

666679942 is a wasteful number, since it uses less digits than its factorization.

666679942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18615.

The product of its digits is 5878656, while the sum is 55.

The square root of 666679942 is about 25820.1460491609. The cubic root of 666679942 is about 873.5862632337.

The spelling of 666679942 in words is "six hundred sixty-six million, six hundred seventy-nine thousand, nine hundred forty-two".