666631051 has 2 divisors, whose sum is σ = 666631052. Its totient is φ = 666631050.

The previous prime is 666631019. The next prime is 666631061. The reversal of 666631051 is 150136666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666631051 - 2⁵ = 666631019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666630998 and 666631016.

It is not a weakly prime, because it can be changed into another prime (666631061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333315525 + 333315526.

It is an arithmetic number, because the mean of its divisors is an integer number (333315526).

Almost surely, 2^666631051 is an apocalyptic number.

666631051 is a deficient number, since it is larger than the sum of its proper divisors (1).

666631051 is an equidigital number, since it uses as much as digits as its factorization.

666631051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 666631051 is about 25819.1992710851. The cubic root of 666631051 is about 873.5649078839.

The spelling of 666631051 in words is "six hundred sixty-six million, six hundred thirty-one thousand, fifty-one".