664774992493920 has 1152 divisors, whose sum is σ = 2982411798912000. Its totient is φ = 130634570465280.

The previous prime is 664774992493879. The next prime is 664774992493951. The reversal of 664774992493920 is 29394299477466.

664774992493920 is a `hidden beast` number, since 6 + 6 + 4 + 77 + 499 + 2 + 4 + 9 + 39 + 20 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 664774992493920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1198446396 + ... + 1199000964.

It is an arithmetic number, because the mean of its divisors is an integer number (2588899131000).

Almost surely, 2^{664774992493920} is an apocalyptic number.

664774992493920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664774992493920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1491205899456000).

664774992493920 is an abundant number, since it is smaller than the sum of its proper divisors (2317636806418080).

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

664774992493920 is a wasteful number, since it uses less digits than its factorization.

664774992493920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555196 (or 555185 counting only the distinct ones).

The product of its (nonzero) digits is 8888527872, while the sum is 81.

The spelling of 664774992493920 in words is "six hundred sixty-four trillion, seven hundred seventy-four billion, nine hundred ninety-two million, four hundred ninety-three thousand, nine hundred twenty".