664973520 has 40 divisors (see below), whose sum is σ = 2061418656. Its totient is φ = 177326208.

The previous prime is 664973503. The next prime is 664973527. The reversal of 664973520 is 25379466.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664973527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1385122 + ... + 1385601.

Almost surely, 2^664973520 is an apocalyptic number.

664973520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664973520 is an abundant number, since it is smaller than the sum of its proper divisors (1396445136).

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

664973520 is a wasteful number, since it uses less digits than its factorization.

664973520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2770739 (or 2770733 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 42.

The square root of 664973520 is about 25787.0804861659. The cubic root of 664973520 is about 872.8402878422.

The spelling of 664973520 in words is "six hundred sixty-four million, nine hundred seventy-three thousand, five hundred twenty".