666879959 has 2 divisors, whose sum is σ = 666879960. Its totient is φ = 666879958.

The previous prime is 666879929. The next prime is 666880007. The reversal of 666879959 is 959978666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666879959 - 2²⁴ = 650102743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666879895 and 666879904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666879929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333439979 + 333439980.

It is an arithmetic number, because the mean of its divisors is an integer number (333439980).

Almost surely, 2^666879959 is an apocalyptic number.

666879959 is a deficient number, since it is larger than the sum of its proper divisors (1).

666879959 is an equidigital number, since it uses as much as digits as its factorization.

666879959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 44089920, while the sum is 65.

The square root of 666879959 is about 25824.0190326758. The cubic root of 666879959 is about 873.6736188103.

The spelling of 666879959 in words is "six hundred sixty-six million, eight hundred seventy-nine thousand, nine hundred fifty-nine".