81938516 has 24 divisors (see below), whose sum is σ = 156673440. Its totient is φ = 37186400.

The previous prime is 81938501. The next prime is 81938533. The reversal of 81938516 is 61583918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40415 + ... + 42393.

It is an arithmetic number, because the mean of its divisors is an integer number (6528060).

Almost surely, 2^81938516 is an apocalyptic number.

It is an amenable number.

81938516 is a deficient number, since it is larger than the sum of its proper divisors (74734924).

81938516 is a wasteful number, since it uses less digits than its factorization.

81938516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2935 (or 2933 counting only the distinct ones).

The product of its digits is 51840, while the sum is 41.

The square root of 81938516 is about 9051.9896155486. The cubic root of 81938516 is about 434.3395376463.

The spelling of 81938516 in words is "eighty-one million, nine hundred thirty-eight thousand, five hundred sixteen".