81913115 has 8 divisors (see below), whose sum is σ = 99480528. Its totient is φ = 64740640.

The previous prime is 81913099. The next prime is 81913127. The reversal of 81913115 is 51131918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81913115 - 2⁴ = 81913099 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98276 + ... + 99105.

It is an arithmetic number, because the mean of its divisors is an integer number (12435066).

Almost surely, 2^81913115 is an apocalyptic number.

81913115 is a deficient number, since it is larger than the sum of its proper divisors (17567413).

81913115 is a wasteful number, since it uses less digits than its factorization.

81913115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197469.

The product of its digits is 1080, while the sum is 29.

The square root of 81913115 is about 9050.5864450874. The cubic root of 81913115 is about 434.2946511494.

It can be divided in two parts, 81913 and 115, that added together give a palindrome (82028).

The spelling of 81913115 in words is "eighty-one million, nine hundred thirteen thousand, one hundred fifteen".