664576785972 has 576 divisors, whose sum is σ = 2074248933120. Its totient is φ = 183097221120.

The previous prime is 664576785967. The next prime is 664576785979. The reversal of 664576785972 is 279587675466.

664576785972 is a `hidden beast` number, since 6 + 6 + 457 + 6 + 7 + 85 + 97 + 2 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 664576785972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664576785979) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1915206703 + ... + 1915207049.

It is an arithmetic number, because the mean of its divisors is an integer number (3601126620).

Almost surely, 2^664576785972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664576785972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1037124466560).

664576785972 is an abundant number, since it is smaller than the sum of its proper divisors (1409672147148).

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

664576785972 is a wasteful number, since it uses less digits than its factorization.

664576785972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669 (or 650 counting only the distinct ones).

The product of its digits is 1066867200, while the sum is 72.

The spelling of 664576785972 in words is "six hundred sixty-four billion, five hundred seventy-six million, seven hundred eighty-five thousand, nine hundred seventy-two".