81125915 has 48 divisors (see below), whose sum is σ = 115246080. Its totient is φ = 54587520.

The previous prime is 81125893. The next prime is 81125929. The reversal of 81125915 is 51952118.

It is not a de Polignac number, because 81125915 - 2⁶ = 81125851 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 497624 + ... + 497786.

It is an arithmetic number, because the mean of its divisors is an integer number (2400960).

Almost surely, 2^81125915 is an apocalyptic number.

81125915 is a deficient number, since it is larger than the sum of its proper divisors (34120165).

81125915 is a wasteful number, since it uses less digits than its factorization.

81125915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 231 counting only the distinct ones).

The product of its digits is 3600, while the sum is 32.

The square root of 81125915 is about 9006.9925613381. The cubic root of 81125915 is about 432.8989536057.

The spelling of 81125915 in words is "eighty-one million, one hundred twenty-five thousand, nine hundred fifteen".