660695993 has 2 divisors, whose sum is σ = 660695994. Its totient is φ = 660695992.

The previous prime is 660695927. The next prime is 660696031. The reversal of 660695993 is 399596066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 659873344 + 822649 = 25688^2 + 907^2 .

It is a cyclic number.

It is not a de Polignac number, because 660695993 - 2²⁴ = 643918777 is a prime.

It is not a weakly prime, because it can be changed into another prime (660695923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330347996 + 330347997.

It is an arithmetic number, because the mean of its divisors is an integer number (330347997).

Almost surely, 2^660695993 is an apocalyptic number.

It is an amenable number.

660695993 is a deficient number, since it is larger than the sum of its proper divisors (1).

660695993 is an equidigital number, since it uses as much as digits as its factorization.

660695993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2361960, while the sum is 53.

The square root of 660695993 is about 25704.0073334879. The cubic root of 660695993 is about 870.9647082724.

The spelling of 660695993 in words is "six hundred sixty million, six hundred ninety-five thousand, nine hundred ninety-three".