664678680 has 32 divisors (see below), whose sum is σ = 1994036400. Its totient is φ = 177247616.

The previous prime is 664678643. The next prime is 664678681. The reversal of 664678680 is 86876466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664678681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2769375 + ... + 2769614.

Almost surely, 2^664678680 is an apocalyptic number.

664678680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664678680 is an abundant number, since it is smaller than the sum of its proper divisors (1329357720).

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

664678680 is a wasteful number, since it uses less digits than its factorization.

664678680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5539003 (or 5538999 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 51.

The square root of 664678680 is about 25781.3630361158. The cubic root of 664678680 is about 872.7112670281.

The spelling of 664678680 in words is "six hundred sixty-four million, six hundred seventy-eight thousand, six hundred eighty".