663695917 has 2 divisors, whose sum is σ = 663695918. Its totient is φ = 663695916.

The previous prime is 663695881. The next prime is 663695933. The reversal of 663695917 is 719596366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490799716 + 172896201 = 22154^2 + 13149^2 .

It is a cyclic number.

It is not a de Polignac number, because 663695917 - 2¹¹ = 663693869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663693917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331847958 + 331847959.

It is an arithmetic number, because the mean of its divisors is an integer number (331847959).

Almost surely, 2^663695917 is an apocalyptic number.

It is an amenable number.

663695917 is a deficient number, since it is larger than the sum of its proper divisors (1).

663695917 is an equidigital number, since it uses as much as digits as its factorization.

663695917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1837080, while the sum is 52.

The square root of 663695917 is about 25762.2964232616. The cubic root of 663695917 is about 872.2809380992.

The spelling of 663695917 in words is "six hundred sixty-three million, six hundred ninety-five thousand, nine hundred seventeen".