81136875 has 40 divisors (see below), whose sum is σ = 136768720. Its totient is φ = 42768000.

The previous prime is 81136873. The next prime is 81136879. The reversal of 81136875 is 57863118.

It is not a de Polignac number, because 81136875 - 2¹ = 81136873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81136873) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 204177 + ... + 204573.

It is an arithmetic number, because the mean of its divisors is an integer number (3419218).

Almost surely, 2^81136875 is an apocalyptic number.

81136875 is a deficient number, since it is larger than the sum of its proper divisors (55631845).

81136875 is a wasteful number, since it uses less digits than its factorization.

81136875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 514 counting only the distinct ones).

The product of its digits is 40320, while the sum is 39.

The square root of 81136875 is about 9007.6009569696. The cubic root of 81136875 is about 432.9184474131.

The spelling of 81136875 in words is "eighty-one million, one hundred thirty-six thousand, eight hundred seventy-five".