666879901 has 2 divisors, whose sum is σ = 666879902. Its totient is φ = 666879900.

The previous prime is 666879833. The next prime is 666879929. The reversal of 666879901 is 109978666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 445167801 + 221712100 = 21099^2 + 14890^2 .

It is a cyclic number.

It is not a de Polignac number, because 666879901 - 2¹⁷ = 666748829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666879001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333439950 + 333439951.

It is an arithmetic number, because the mean of its divisors is an integer number (333439951).

Almost surely, 2^666879901 is an apocalyptic number.

It is an amenable number.

666879901 is a deficient number, since it is larger than the sum of its proper divisors (1).

666879901 is an equidigital number, since it uses as much as digits as its factorization.

666879901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 52.

The square root of 666879901 is about 25824.0179096902. The cubic root of 666879901 is about 873.6735934819.

The spelling of 666879901 in words is "six hundred sixty-six million, eight hundred seventy-nine thousand, nine hundred one".