664632172800 has 432 divisors, whose sum is σ = 2496607498560. Its totient is φ = 172910592000.

The previous prime is 664632172733. The next prime is 664632172807. The reversal of 664632172800 is 8271236466.

664632172800 is a `hidden beast` number, since 6 + 6 + 4 + 632 + 1 + 7 + 2 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (664632172807) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7037895 + ... + 7131705.

Almost surely, 2^664632172800 is an apocalyptic number.

664632172800 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 664632172800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1248303749280).

664632172800 is an abundant number, since it is smaller than the sum of its proper divisors (1831975325760).

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

664632172800 is a wasteful number, since it uses less digits than its factorization.

664632172800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93887 (or 93862 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 664632172800 in words is "six hundred sixty-four billion, six hundred thirty-two million, one hundred seventy-two thousand, eight hundred".