81938872 has 16 divisors (see below), whose sum is σ = 153802800. Its totient is φ = 40924800.

The previous prime is 81938867. The next prime is 81938893. The reversal of 81938872 is 27883918.

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, 2997 + ... + 13147.

It is an arithmetic number, because the mean of its divisors is an integer number (9612675).

Almost surely, 2^81938872 is an apocalyptic number.

It is an amenable number.

81938872 is a deficient number, since it is larger than the sum of its proper divisors (71863928).

81938872 is a wasteful number, since it uses less digits than its factorization.

81938872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11166 (or 11162 counting only the distinct ones).

The product of its digits is 193536, while the sum is 46.

The square root of 81938872 is about 9052.0092797124. The cubic root of 81938872 is about 434.3401666735.

The spelling of 81938872 in words is "eighty-one million, nine hundred thirty-eight thousand, eight hundred seventy-two".