641369657 has 2 divisors, whose sum is σ = 641369658. Its totient is φ = 641369656.

The previous prime is 641369623. The next prime is 641369671. The reversal of 641369657 is 756963146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 388050601 + 253319056 = 19699^2 + 15916^2 .

It is a cyclic number.

It is not a de Polignac number, because 641369657 - 2⁶ = 641369593 is a prime.

It is a super-2 number, since 2×641369657² = 822710073840595298, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (641309657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320684828 + 320684829.

It is an arithmetic number, because the mean of its divisors is an integer number (320684829).

Almost surely, 2^641369657 is an apocalyptic number.

It is an amenable number.

641369657 is a deficient number, since it is larger than the sum of its proper divisors (1).

641369657 is an equidigital number, since it uses as much as digits as its factorization.

641369657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 816480, while the sum is 47.

The square root of 641369657 is about 25325.2770369842. The cubic root of 641369657 is about 862.3881956035.

The spelling of 641369657 in words is "six hundred forty-one million, three hundred sixty-nine thousand, six hundred fifty-seven".