664173860400 has 180 divisors, whose sum is σ = 2328630536232. Its totient is φ = 175287029760.

The previous prime is 664173860381. The next prime is 664173860401. The reversal of 664173860400 is 4068371466.

It is a happy number.

664173860400 is a `hidden beast` number, since 6 + 6 + 4 + 1 + 7 + 38 + 604 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×664173860400² (a number of 24 digits) contains 22 as substring.

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 (664173860401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 601794 + ... + 1300193.

Almost surely, 2^664173860400 is an apocalyptic number.

664173860400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664173860400 is an abundant number, since it is smaller than the sum of its proper divisors (1664456675832).

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

664173860400 is a wasteful number, since it uses less digits than its factorization.

664173860400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1902108 (or 1902094 counting only the distinct ones).

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

The spelling of 664173860400 in words is "six hundred sixty-four billion, one hundred seventy-three million, eight hundred sixty thousand, four hundred".