664185844 has 12 divisors (see below), whose sum is σ = 1328371744. Its totient is φ = 284651064.

The previous prime is 664185829. The next prime is 664185871. The reversal of 664185844 is 448581466.

664185844 is an admirable number.

It is a super-2 number, since 2×664185844² = 882285670739984672, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664185794 and 664185803.

It is a congruent 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, 11860434 + ... + 11860489.

Almost surely, 2^664185844 is an apocalyptic number.

It is an amenable number.

664185844 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.

664185844 is a wasteful number, since it uses less digits than its factorization.

664185844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23720934 (or 23720932 counting only the distinct ones).

The product of its digits is 737280, while the sum is 46.

The square root of 664185844 is about 25771.8032741211. The cubic root of 664185844 is about 872.4955187330.

The spelling of 664185844 in words is "six hundred sixty-four million, one hundred eighty-five thousand, eight hundred forty-four".