664040257 has 8 divisors (see below), whose sum is σ = 669360384. Its totient is φ = 658741488.

The previous prime is 664040249. The next prime is 664040261. The reversal of 664040257 is 752040466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664040257 - 2³ = 664040249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664040207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60258 + ... + 70420.

It is an arithmetic number, because the mean of its divisors is an integer number (83670048).

Almost surely, 2^664040257 is an apocalyptic number.

It is an amenable number.

664040257 is a deficient number, since it is larger than the sum of its proper divisors (5320127).

664040257 is a wasteful number, since it uses less digits than its factorization.

664040257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10679.

The product of its (nonzero) digits is 40320, while the sum is 34.

The square root of 664040257 is about 25768.9785789037. The cubic root of 664040257 is about 872.4317648462.

The spelling of 664040257 in words is "six hundred sixty-four million, forty thousand, two hundred fifty-seven".