664405600 has 72 divisors (see below), whose sum is σ = 1692547920. Its totient is φ = 254200320.

The previous prime is 664405579. The next prime is 664405601. The reversal of 664405600 is 6504466.

It is a super-2 number, since 2×664405600² = 882869602622720000, which contains 22 as substring.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664405601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 346 + ... + 36454.

It is an arithmetic number, because the mean of its divisors is an integer number (23507610).

Almost surely, 2^664405600 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 664405600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (846273960).

664405600 is an abundant number, since it is smaller than the sum of its proper divisors (1028142320).

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

664405600 is a wasteful number, since it uses less digits than its factorization.

664405600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36152 (or 36139 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 664405600 is about 25776.0664182881. The cubic root of 664405600 is about 872.5917342649.

The spelling of 664405600 in words is "six hundred sixty-four million, four hundred five thousand, six hundred".