664039680 has 288 divisors, whose sum is σ = 2251670400. Its totient is φ = 166526976.

The previous prime is 664039657. The next prime is 664039687. The reversal of 664039680 is 86930466.

It is a super-2 number, since 2×664039680² = 881897393229004800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664039687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7461076 + ... + 7461164.

It is an arithmetic number, because the mean of its divisors is an integer number (7818300).

Almost surely, 2^664039680 is an apocalyptic number.

664039680 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 664039680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1125835200).

664039680 is an abundant number, since it is smaller than the sum of its proper divisors (1587630720).

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

664039680 is a wasteful number, since it uses less digits than its factorization.

664039680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 664039680 is about 25768.9673832694. The cubic root of 664039680 is about 872.4315121541.

The spelling of 664039680 in words is "six hundred sixty-four million, thirty-nine thousand, six hundred eighty".