81995288 has 16 divisors (see below), whose sum is σ = 154288680. Its totient is φ = 40851648.

The previous prime is 81995261. The next prime is 81995297. The reversal of 81995288 is 88259918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15845 + ... + 20372.

Almost surely, 2^81995288 is an apocalyptic number.

It is an amenable number.

81995288 is a deficient number, since it is larger than the sum of its proper divisors (72293392).

81995288 is a wasteful number, since it uses less digits than its factorization.

81995288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36506 (or 36502 counting only the distinct ones).

The product of its digits is 414720, while the sum is 50.

The square root of 81995288 is about 9055.1249577242. The cubic root of 81995288 is about 434.4398267928.

The spelling of 81995288 in words is "eighty-one million, nine hundred ninety-five thousand, two hundred eighty-eight".