81140266543 has 24 divisors (see below), whose sum is σ = 97490319360. Its totient is φ = 67265296560.

The previous prime is 81140266513. The next prime is 81140266547. The reversal of 81140266543 is 34566204118.

It is a happy number.

It is not a de Polignac number, because 81140266543 - 2²⁵ = 81106712111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81140266496 and 81140266505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81140266547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2693398 + ... + 2723356.

It is an arithmetic number, because the mean of its divisors is an integer number (4062096640).

Almost surely, 2^81140266543 is an apocalyptic number.

81140266543 is a deficient number, since it is larger than the sum of its proper divisors (16350052817).

81140266543 is a wasteful number, since it uses less digits than its factorization.

81140266543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31787 (or 31780 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 81140266543 in words is "eighty-one billion, one hundred forty million, two hundred sixty-six thousand, five hundred forty-three".