81118223 has 4 divisors (see below), whose sum is σ = 81475800. Its totient is φ = 80760648.

The previous prime is 81118211. The next prime is 81118229. The reversal of 81118223 is 32281118.

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

It is a cyclic number.

It is not a de Polignac number, because 81118223 - 2⁴ = 81118207 is a prime.

It is a super-2 number, since 2×81118223² = 13160332205355458, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81118192 and 81118201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81118229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178448 + ... + 178901.

It is an arithmetic number, because the mean of its divisors is an integer number (20368950).

Almost surely, 2^81118223 is an apocalyptic number.

81118223 is a deficient number, since it is larger than the sum of its proper divisors (357577).

81118223 is a wasteful number, since it uses less digits than its factorization.

81118223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357576.

The product of its digits is 768, while the sum is 26.

The square root of 81118223 is about 9006.5655496421. The cubic root of 81118223 is about 432.8852713194.

The spelling of 81118223 in words is "eighty-one million, one hundred eighteen thousand, two hundred twenty-three".