669256979 has 2 divisors, whose sum is σ = 669256980. Its totient is φ = 669256978.

The previous prime is 669256963. The next prime is 669257011. The reversal of 669256979 is 979652966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 669256979 - 2⁴ = 669256963 is a prime.

It is not a weakly prime, because it can be changed into another prime (669256879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334628489 + 334628490.

It is an arithmetic number, because the mean of its divisors is an integer number (334628490).

Almost surely, 2^669256979 is an apocalyptic number.

669256979 is a deficient number, since it is larger than the sum of its proper divisors (1).

669256979 is an equidigital number, since it uses as much as digits as its factorization.

669256979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11022480, while the sum is 59.

The square root of 669256979 is about 25870.0015268650. The cubic root of 669256979 is about 874.7104256476.

The spelling of 669256979 in words is "six hundred sixty-nine million, two hundred fifty-six thousand, nine hundred seventy-nine".