81113215243 has 4 divisors (see below), whose sum is σ = 81116259840. Its totient is φ = 81110170648.

The previous prime is 81113215207. The next prime is 81113215247. The reversal of 81113215243 is 34251231118.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81113215243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81113215247) 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, 1481980 + ... + 1535737.

It is an arithmetic number, because the mean of its divisors is an integer number (20279064960).

Almost surely, 2^81113215243 is an apocalyptic number.

81113215243 is a deficient number, since it is larger than the sum of its proper divisors (3044597).

81113215243 is a wasteful number, since it uses less digits than its factorization.

81113215243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3044596.

The product of its digits is 5760, while the sum is 31.

The spelling of 81113215243 in words is "eighty-one billion, one hundred thirteen million, two hundred fifteen thousand, two hundred forty-three".