81115337 has 4 divisors (see below), whose sum is σ = 82226580. Its totient is φ = 80004096.

The previous prime is 81115327. The next prime is 81115339. The reversal of 81115337 is 73351118.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51998521 + 29116816 = 7211^2 + 5396^2 .

It is a cyclic number.

It is not a de Polignac number, because 81115337 - 2⁸ = 81115081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81115339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 555512 + ... + 555657.

It is an arithmetic number, because the mean of its divisors is an integer number (20556645).

Almost surely, 2^81115337 is an apocalyptic number.

It is an amenable number.

81115337 is a deficient number, since it is larger than the sum of its proper divisors (1111243).

81115337 is a wasteful number, since it uses less digits than its factorization.

81115337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111242.

The product of its digits is 2520, while the sum is 29.

The square root of 81115337 is about 9006.4053317625. The cubic root of 81115337 is about 432.8801375707.

The spelling of 81115337 in words is "eighty-one million, one hundred fifteen thousand, three hundred thirty-seven".