81432188 has 12 divisors (see below), whose sum is σ = 142607640. Its totient is φ = 40687152.

The previous prime is 81432187. The next prime is 81432199. The reversal of 81432188 is 88123418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81432187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131 + ... + 12762.

It is an arithmetic number, because the mean of its divisors is an integer number (11883970).

Almost surely, 2^81432188 is an apocalyptic number.

It is an amenable number.

81432188 is a deficient number, since it is larger than the sum of its proper divisors (61175452).

81432188 is a wasteful number, since it uses less digits than its factorization.

81432188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14476 (or 14474 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 81432188 is about 9023.9785017474. The cubic root of 81432188 is about 433.4430409933.

The spelling of 81432188 in words is "eighty-one million, four hundred thirty-two thousand, one hundred eighty-eight".