660917879 has 2 divisors, whose sum is σ = 660917880. Its totient is φ = 660917878.

The previous prime is 660917867. The next prime is 660917899. The reversal of 660917879 is 978719066.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660917879 - 2⁴ = 660917863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 660917879.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660917809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330458939 + 330458940.

It is an arithmetic number, because the mean of its divisors is an integer number (330458940).

Almost surely, 2^660917879 is an apocalyptic number.

660917879 is a deficient number, since it is larger than the sum of its proper divisors (1).

660917879 is an equidigital number, since it uses as much as digits as its factorization.

660917879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 660917879 is about 25708.3231464053. The cubic root of 660917879 is about 871.0621980142.

The spelling of 660917879 in words is "six hundred sixty million, nine hundred seventeen thousand, eight hundred seventy-nine".