81118880719 has 4 divisors (see below), whose sum is σ = 81237649896. Its totient is φ = 81000111544.

The previous prime is 81118880699. The next prime is 81118880723. The reversal of 81118880719 is 91708881118.

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-81118880719 is a prime.

It is a super-2 number, since 2×81118880719² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81118880729) 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, 59383564 + ... + 59384929.

It is an arithmetic number, because the mean of its divisors is an integer number (20309412474).

Almost surely, 2^81118880719 is an apocalyptic number.

81118880719 is a deficient number, since it is larger than the sum of its proper divisors (118769177).

81118880719 is a wasteful number, since it uses less digits than its factorization.

81118880719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118769176.

The product of its (nonzero) digits is 258048, while the sum is 52.

The spelling of 81118880719 in words is "eighty-one billion, one hundred eighteen million, eight hundred eighty thousand, seven hundred nineteen".