664878400 has 84 divisors (see below), whose sum is σ = 1722201280. Its totient is φ = 251942400.

The previous prime is 664878397. The next prime is 664878407. The reversal of 664878400 is 4878466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664878407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19465 + ... + 41335.

Almost surely, 2^664878400 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 664878400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (861100640).

664878400 is an abundant number, since it is smaller than the sum of its proper divisors (1057322880).

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

664878400 is a wasteful number, since it uses less digits than its factorization.

664878400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21912 (or 21897 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 43.

The square root of 664878400 is about 25785.2360857914. The cubic root of 664878400 is about 872.7986678756.

The spelling of 664878400 in words is "six hundred sixty-four million, eight hundred seventy-eight thousand, four hundred".