81839228 has 12 divisors (see below), whose sum is σ = 143454360. Its totient is φ = 40852272.

The previous prime is 81839209. The next prime is 81839243. The reversal of 81839228 is 82293818.

It is a happy number.

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, 14051 + ... + 19002.

It is an arithmetic number, because the mean of its divisors is an integer number (11954530).

Almost surely, 2^81839228 is an apocalyptic number.

It is an amenable number.

81839228 is a deficient number, since it is larger than the sum of its proper divisors (61615132).

81839228 is a wasteful number, since it uses less digits than its factorization.

81839228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33676 (or 33674 counting only the distinct ones).

The product of its digits is 55296, while the sum is 41.

The square root of 81839228 is about 9046.5036340014. The cubic root of 81839228 is about 434.1640315210.

The spelling of 81839228 in words is "eighty-one million, eight hundred thirty-nine thousand, two hundred twenty-eight".