81488815 has 16 divisors (see below), whose sum is σ = 103201920. Its totient is φ = 61598880.

The previous prime is 81488807. The next prime is 81488843. The reversal of 81488815 is 51888418.

It is not a de Polignac number, because 81488815 - 2³ = 81488807 is a prime.

It is a congruent number.

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, 45772 + ... + 47518.

It is an arithmetic number, because the mean of its divisors is an integer number (6450120).

Almost surely, 2^81488815 is an apocalyptic number.

81488815 is a deficient number, since it is larger than the sum of its proper divisors (21713105).

81488815 is a wasteful number, since it uses less digits than its factorization.

81488815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2262.

The product of its digits is 81920, while the sum is 43.

The square root of 81488815 is about 9027.1155415227. The cubic root of 81488815 is about 433.5434881365.

The spelling of 81488815 in words is "eighty-one million, four hundred eighty-eight thousand, eight hundred fifteen".