1581111213791 has 12 divisors (see below), whose sum is σ = 1680858386760. Its totient is φ = 1486733875440.

The previous prime is 1581111213733. The next prime is 1581111213853. The reversal of 1581111213791 is 1973121111851.

It is a happy number.

It is not a de Polignac number, because 1581111213791 - 2³⁰ = 1580037471967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1581111213701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25298180 + ... + 25360601.

It is an arithmetic number, because the mean of its divisors is an integer number (140071532230).

Almost surely, 2^{1581111213791} is an apocalyptic number.

1581111213791 is a deficient number, since it is larger than the sum of its proper divisors (99747172969).

1581111213791 is an equidigital number, since it uses as much as digits as its factorization.

1581111213791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50658886 (or 50658863 counting only the distinct ones).

The product of its digits is 15120, while the sum is 41.

The spelling of 1581111213791 in words is "one trillion, five hundred eighty-one billion, one hundred eleven million, two hundred thirteen thousand, seven hundred ninety-one".