64665257 has 2 divisors, whose sum is σ = 64665258. Its totient is φ = 64665256.

The previous prime is 64665221. The next prime is 64665269. The reversal of 64665257 is 75256646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63186601 + 1478656 = 7949^2 + 1216^2 .

It is a cyclic number.

It is not a de Polignac number, because 64665257 - 2⁸ = 64665001 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64665277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32332628 + 32332629.

It is an arithmetic number, because the mean of its divisors is an integer number (32332629).

Almost surely, 2^64665257 is an apocalyptic number.

It is an amenable number.

64665257 is a deficient number, since it is larger than the sum of its proper divisors (1).

64665257 is an equidigital number, since it uses as much as digits as its factorization.

64665257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 41.

The square root of 64665257 is about 8041.4710718873. The cubic root of 64665257 is about 401.3811774662.

The spelling of 64665257 in words is "sixty-four million, six hundred sixty-five thousand, two hundred fifty-seven".