661328188 has 6 divisors (see below), whose sum is σ = 1157324336. Its totient is φ = 330664092.

The previous prime is 661328167. The next prime is 661328189. The reversal of 661328188 is 881823166.

661328188 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661328189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82666020 + ... + 82666027.

Almost surely, 2^661328188 is an apocalyptic number.

It is an amenable number.

661328188 is a deficient number, since it is larger than the sum of its proper divisors (495996148).

661328188 is a wasteful number, since it uses less digits than its factorization.

661328188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165332051 (or 165332049 counting only the distinct ones).

The product of its digits is 110592, while the sum is 43.

The square root of 661328188 is about 25716.3019892052. The cubic root of 661328188 is about 871.2424174410.

The spelling of 661328188 in words is "six hundred sixty-one million, three hundred twenty-eight thousand, one hundred eighty-eight".