666879929 has 2 divisors, whose sum is σ = 666879930. Its totient is φ = 666879928.

The previous prime is 666879901. The next prime is 666879959. The reversal of 666879929 is 929978666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 621006400 + 45873529 = 24920^2 + 6773^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666879929 is a prime.

It is not a weakly prime, because it can be changed into another prime (666879959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333439964 + 333439965.

It is an arithmetic number, because the mean of its divisors is an integer number (333439965).

Almost surely, 2^666879929 is an apocalyptic number.

It is an amenable number.

666879929 is a deficient number, since it is larger than the sum of its proper divisors (1).

666879929 is an equidigital number, since it uses as much as digits as its factorization.

666879929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17635968, while the sum is 62.

The square root of 666879929 is about 25824.0184518212. The cubic root of 666879929 is about 873.6736057094.

The spelling of 666879929 in words is "six hundred sixty-six million, eight hundred seventy-nine thousand, nine hundred twenty-nine".