81128115 has 16 divisors (see below), whose sum is σ = 144228000. Its totient is φ = 43268256.

The previous prime is 81128093. The next prime is 81128123. The reversal of 81128115 is 51182118.

It is not a de Polignac number, because 81128115 - 2¹⁰ = 81127091 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 300340 + ... + 300609.

It is an arithmetic number, because the mean of its divisors is an integer number (9014250).

Almost surely, 2^81128115 is an apocalyptic number.

81128115 is a deficient number, since it is larger than the sum of its proper divisors (63099885).

81128115 is a wasteful number, since it uses less digits than its factorization.

81128115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600963 (or 600957 counting only the distinct ones).

The product of its digits is 640, while the sum is 27.

The square root of 81128115 is about 9007.1146878454. The cubic root of 81128115 is about 432.9028667371.

The spelling of 81128115 in words is "eighty-one million, one hundred twenty-eight thousand, one hundred fifteen".