660971807 has 2 divisors, whose sum is σ = 660971808. Its totient is φ = 660971806.

The previous prime is 660971789. The next prime is 660971833. The reversal of 660971807 is 708179066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660971807 - 2⁶ = 660971743 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (630971807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330485903 + 330485904.

It is an arithmetic number, because the mean of its divisors is an integer number (330485904).

Almost surely, 2^660971807 is an apocalyptic number.

660971807 is a deficient number, since it is larger than the sum of its proper divisors (1).

660971807 is an equidigital number, since it uses as much as digits as its factorization.

660971807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 660971807 is about 25709.3719682142. The cubic root of 660971807 is about 871.0858889881.

The spelling of 660971807 in words is "six hundred sixty million, nine hundred seventy-one thousand, eight hundred seven".