657717397 has 2 divisors, whose sum is σ = 657717398. Its totient is φ = 657717396.

The previous prime is 657717349. The next prime is 657717413. The reversal of 657717397 is 793717756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 657717316 + 81 = 25646^2 + 9^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-657717397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (657717497) 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, 328858698 + 328858699.

It is an arithmetic number, because the mean of its divisors is an integer number (328858699).

Almost surely, 2^657717397 is an apocalyptic number.

It is an amenable number.

657717397 is a deficient number, since it is larger than the sum of its proper divisors (1).

657717397 is an equidigital number, since it uses as much as digits as its factorization.

657717397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944810, while the sum is 52.

The square root of 657717397 is about 25646.0015791936. The cubic root of 657717397 is about 869.6538883961.

The spelling of 657717397 in words is "six hundred fifty-seven million, seven hundred seventeen thousand, three hundred ninety-seven".