664640900 has 324 divisors, whose sum is σ = 1974092400. Its totient is φ = 192931200.

The previous prime is 664640827. The next prime is 664640929. The reversal of 664640900 is 9046466.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 11265071 + ... + 11265129.

Almost surely, 2^664640900 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 664640900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (987046200).

664640900 is an abundant number, since it is smaller than the sum of its proper divisors (1309451500).

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

664640900 is a wasteful number, since it uses less digits than its factorization.

664640900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 664640900 is about 25780.6303258861. The cubic root of 664640900 is about 872.6947318925.

The spelling of 664640900 in words is "six hundred sixty-four million, six hundred forty thousand, nine hundred".