664188 has 24 divisors (see below), whose sum is σ = 1771392. Its totient is φ = 189744.

The previous prime is 664177. The next prime is 664193. The reversal of 664188 is 881466.

It is a super-2 number, since 2×664188² = 882291398688, which contains 22 as substring.

It is a congruent number.

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, 3870 + ... + 4037.

It is an arithmetic number, because the mean of its divisors is an integer number (73808).

2⁶⁶⁴¹⁸⁸ is an apocalyptic number.

It is an amenable number.

664188 is an abundant number, since it is smaller than the sum of its proper divisors (1107204).

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

664188 is a wasteful number, since it uses less digits than its factorization.

664188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7921 (or 7919 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 664188 is about 814.9773002974. The cubic root of 664188 is about 87.2496462795.

The spelling of 664188 in words is "six hundred sixty-four thousand, one hundred eighty-eight".