81715893 has 16 divisors (see below), whose sum is σ = 124663296. Its totient is φ = 46640880.

The previous prime is 81715873. The next prime is 81715901. The reversal of 81715893 is 39851718.

It is not a de Polignac number, because 81715893 - 2⁵ = 81715861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81715873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22930 + ... + 26252.

It is an arithmetic number, because the mean of its divisors is an integer number (7791456).

Almost surely, 2^81715893 is an apocalyptic number.

It is an amenable number.

81715893 is a deficient number, since it is larger than the sum of its proper divisors (42947403).

81715893 is a wasteful number, since it uses less digits than its factorization.

81715893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504.

The product of its digits is 60480, while the sum is 42.

The square root of 81715893 is about 9039.6843418341. The cubic root of 81715893 is about 433.9458209956.

The spelling of 81715893 in words is "eighty-one million, seven hundred fifteen thousand, eight hundred ninety-three".