81811273941 has 32 divisors (see below), whose sum is σ = 124039987200. Its totient is φ = 53268568560.

The previous prime is 81811273931. The next prime is 81811273949. The reversal of 81811273941 is 14937211818.

It is a happy number.

It is not a de Polignac number, because 81811273941 - 2⁹ = 81811273429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81811273949) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 540556 + ... + 675146.

It is an arithmetic number, because the mean of its divisors is an integer number (3876249600).

Almost surely, 2^81811273941 is an apocalyptic number.

It is an amenable number.

81811273941 is a deficient number, since it is larger than the sum of its proper divisors (42228713259).

81811273941 is a wasteful number, since it uses less digits than its factorization.

81811273941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135126 (or 135120 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The spelling of 81811273941 in words is "eighty-one billion, eight hundred eleven million, two hundred seventy-three thousand, nine hundred forty-one".