664317751 has 4 divisors (see below), whose sum is σ = 668157912. Its totient is φ = 660477592.

The previous prime is 664317733. The next prime is 664317781. The reversal of 664317751 is 157713466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664317751 - 2⁷ = 664317623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664317781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1919821 + ... + 1920166.

It is an arithmetic number, because the mean of its divisors is an integer number (167039478).

Almost surely, 2^664317751 is an apocalyptic number.

664317751 is a deficient number, since it is larger than the sum of its proper divisors (3840161).

664317751 is a wasteful number, since it uses less digits than its factorization.

664317751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3840160.

The product of its digits is 105840, while the sum is 40.

The square root of 664317751 is about 25774.3622811506. The cubic root of 664317751 is about 872.5532739780.

The spelling of 664317751 in words is "six hundred sixty-four million, three hundred seventeen thousand, seven hundred fifty-one".