666929691 has 12 divisors (see below), whose sum is σ = 994418880. Its totient is φ = 430277040.

The previous prime is 666929639. The next prime is 666929701. The reversal of 666929691 is 196929666.

It is a happy number.

It is not a de Polignac number, because 666929691 - 2¹¹ = 666927643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666929191) 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 11 ways as a sum of consecutive naturals, for example, 1194936 + ... + 1195493.

It is an arithmetic number, because the mean of its divisors is an integer number (82868240).

Almost surely, 2^666929691 is an apocalyptic number.

666929691 is a deficient number, since it is larger than the sum of its proper divisors (327489189).

666929691 is a wasteful number, since it uses less digits than its factorization.

666929691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2390466 (or 2390463 counting only the distinct ones).

The product of its digits is 1889568, while the sum is 54.

The square root of 666929691 is about 25824.9819167410. The cubic root of 666929691 is about 873.6953360903.

The spelling of 666929691 in words is "six hundred sixty-six million, nine hundred twenty-nine thousand, six hundred ninety-one".