81140266784 has 24 divisors (see below), whose sum is σ = 159790261680. Its totient is φ = 40558613056.

The previous prime is 81140266751. The next prime is 81140266793. The reversal of 81140266784 is 48766204118.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244994 + ... + 471489.

It is an arithmetic number, because the mean of its divisors is an integer number (6657927570).

Almost surely, 2^81140266784 is an apocalyptic number.

It is an amenable number.

81140266784 is a deficient number, since it is larger than the sum of its proper divisors (78649994896).

81140266784 is a wasteful number, since it uses less digits than its factorization.

81140266784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720032 (or 720024 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 47.

The spelling of 81140266784 in words is "eighty-one billion, one hundred forty million, two hundred sixty-six thousand, seven hundred eighty-four".