81389432 has 16 divisors (see below), whose sum is σ = 154321200. Its totient is φ = 40237120.

The previous prime is 81389431. The next prime is 81389437. The reversal of 81389432 is 23498318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81389431) 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, 56444 + ... + 57867.

It is an arithmetic number, because the mean of its divisors is an integer number (9645075).

Almost surely, 2^81389432 is an apocalyptic number.

It is an amenable number.

81389432 is a deficient number, since it is larger than the sum of its proper divisors (72931768).

81389432 is a wasteful number, since it uses less digits than its factorization.

81389432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114406 (or 114402 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 81389432 is about 9021.6091691006. The cubic root of 81389432 is about 433.3671679038.

The spelling of 81389432 in words is "eighty-one million, three hundred eighty-nine thousand, four hundred thirty-two".