664395780 has 24 divisors (see below), whose sum is σ = 1860308352. Its totient is φ = 177172192.

The previous prime is 664395761. The next prime is 664395793. The reversal of 664395780 is 87593466.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5536572 + ... + 5536691.

It is an arithmetic number, because the mean of its divisors is an integer number (77512848).

Almost surely, 2^664395780 is an apocalyptic number.

664395780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664395780 is an abundant number, since it is smaller than the sum of its proper divisors (1195912572).

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

664395780 is a wasteful number, since it uses less digits than its factorization.

664395780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11073275 (or 11073273 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 48.

The square root of 664395780 is about 25775.8759308001. The cubic root of 664395780 is about 872.5874352378.

The spelling of 664395780 in words is "six hundred sixty-four million, three hundred ninety-five thousand, seven hundred eighty".