81112491959 has 2 divisors, whose sum is σ = 81112491960. Its totient is φ = 81112491958.

The previous prime is 81112491883. The next prime is 81112492033. The reversal of 81112491959 is 95919421118.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81112491959 - 2⁸ = 81112491703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81112491359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40556245979 + 40556245980.

It is an arithmetic number, because the mean of its divisors is an integer number (40556245980).

Almost surely, 2^81112491959 is an apocalyptic number.

81112491959 is a deficient number, since it is larger than the sum of its proper divisors (1).

81112491959 is an equidigital number, since it uses as much as digits as its factorization.

81112491959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 50.

The spelling of 81112491959 in words is "eighty-one billion, one hundred twelve million, four hundred ninety-one thousand, nine hundred fifty-nine".