664581751361 has 8 divisors (see below), whose sum is σ = 740423769984. Its totient is φ = 591310648720.

The previous prime is 664581751307. The next prime is 664581751363. The reversal of 664581751361 is 163157185466.

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

It is not a de Polignac number, because 664581751361 - 2³⁰ = 663508009537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664581751363) 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, 642728450 + ... + 642729483.

It is an arithmetic number, because the mean of its divisors is an integer number (92552971248).

Almost surely, 2^664581751361 is an apocalyptic number.

It is an amenable number.

664581751361 is a deficient number, since it is larger than the sum of its proper divisors (75842018623).

664581751361 is a wasteful number, since it uses less digits than its factorization.

664581751361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1285457991.

The product of its digits is 3628800, while the sum is 53.

The spelling of 664581751361 in words is "six hundred sixty-four billion, five hundred eighty-one million, seven hundred fifty-one thousand, three hundred sixty-one".