664779600 has 180 divisors, whose sum is σ = 2428639200. Its totient is φ = 167927040.

The previous prime is 664779589. The next prime is 664779607. The reversal of 664779600 is 6977466.

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

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664779607) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 63541 + ... + 73259.

It is an arithmetic number, because the mean of its divisors is an integer number (13492440).

Almost surely, 2^664779600 is an apocalyptic number.

664779600 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 664779600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1214319600).

664779600 is an abundant number, since it is smaller than the sum of its proper divisors (1763859600).

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

664779600 is a wasteful number, since it uses less digits than its factorization.

664779600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9762 (or 9748 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 664779600 is about 25783.3201896110. The cubic root of 664779600 is about 872.7554335137.

The spelling of 664779600 in words is "six hundred sixty-four million, seven hundred seventy-nine thousand, six hundred".