664811929600 has 765 divisors, whose sum is σ = 2082727758183. Its totient is φ = 210402017280.

The previous prime is 664811929567. The next prime is 664811929637. The reversal of 664811929600 is 6929118466.

It is a happy number.

The square root of 664811929600 is 815360.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 171356258304 + 493455671296 = 413952^2 + 702464^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 51139379194 + ... + 51139379206.

Almost surely, 2^664811929600 is an apocalyptic number.

664811929600 is the 815360-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664811929600

664811929600 is an abundant number, since it is smaller than the sum of its proper divisors (1417915828583).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664811929600 is an frugal number, since it uses more digits than its factorization.

664811929600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 52.

The spelling of 664811929600 in words is "six hundred sixty-four billion, eight hundred eleven million, nine hundred twenty-nine thousand, six hundred".