664763904 has 240 divisors, whose sum is σ = 2255935968. Its totient is φ = 184467456.

The previous prime is 664763893. The next prime is 664763923. The reversal of 664763904 is 409367466.

664763904 is a `hidden beast` number, since 6 + 6 + 4 + 7 + 639 + 0 + 4 = 666.

It is a super-2 number, since 2×664763904² = 883822096122642432, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 664763904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1193194 + ... + 1193750.

Almost surely, 2^664763904 is an apocalyptic number.

664763904 is a gapful number since it is divisible by the number (64) 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 664763904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1127967984).

664763904 is an abundant number, since it is smaller than the sum of its proper divisors (1591172064).

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

664763904 is a wasteful number, since it uses less digits than its factorization.

664763904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625 (or 606 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The square root of 664763904 is about 25783.0158049829. The cubic root of 664763904 is about 872.7485646321.

The spelling of 664763904 in words is "six hundred sixty-four million, seven hundred sixty-three thousand, nine hundred four".