664081984 has 28 divisors (see below), whose sum is σ = 1328180224. Its totient is φ = 329422464.

The previous prime is 664081973. The next prime is 664082011. The reversal of 664081984 is 489180466.

664081984 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32724 + ... + 48979.

It is an arithmetic number, because the mean of its divisors is an integer number (47435008).

Almost surely, 2^664081984 is an apocalyptic number.

664081984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

664081984 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

664081984 is a wasteful number, since it uses less digits than its factorization.

664081984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81842 (or 81832 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 46.

The square root of 664081984 is about 25769.7882024669. The cubic root of 664081984 is about 872.4500384360.

The spelling of 664081984 in words is "six hundred sixty-four million, eighty-one thousand, nine hundred eighty-four".