664185872 has 20 divisors (see below), whose sum is σ = 1470697536. Its totient is φ = 284651040.

The previous prime is 664185871. The next prime is 664185911. The reversal of 664185872 is 278581466.

It is a super-2 number, since 2×664185872² = 882285745128800768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664185871) 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 3 ways as a sum of consecutive naturals, for example, 2965004 + ... + 2965227.

Almost surely, 2^664185872 is an apocalyptic number.

It is an amenable number.

664185872 is an abundant number, since it is smaller than the sum of its proper divisors (806511664).

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

664185872 is a wasteful number, since it uses less digits than its factorization.

664185872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5930246 (or 5930240 counting only the distinct ones).

The product of its digits is 645120, while the sum is 47.

The square root of 664185872 is about 25771.8038173505. The cubic root of 664185872 is about 872.4955309935.

The spelling of 664185872 in words is "six hundred sixty-four million, one hundred eighty-five thousand, eight hundred seventy-two".