664722751 has 16 divisors (see below), whose sum is σ = 830810880. Its totient is φ = 516674880.

The previous prime is 664722731. The next prime is 664722761. The reversal of 664722751 is 157227466.

It is a cyclic number.

It is not a de Polignac number, because 664722751 - 2¹⁹ = 664198463 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 (664722731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20940 + ... + 42046.

It is an arithmetic number, because the mean of its divisors is an integer number (51925680).

Almost surely, 2^664722751 is an apocalyptic number.

664722751 is a deficient number, since it is larger than the sum of its proper divisors (166088129).

664722751 is a wasteful number, since it uses less digits than its factorization.

664722751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21534.

The product of its digits is 141120, while the sum is 40.

The square root of 664722751 is about 25782.2177285043. The cubic root of 664722751 is about 872.7305547478.

The spelling of 664722751 in words is "six hundred sixty-four million, seven hundred twenty-two thousand, seven hundred fifty-one".