81040266576 has 30 divisors (see below), whose sum is σ = 226800190890. Its totient is φ = 27013422144.

The previous prime is 81040266569. The next prime is 81040266589. The reversal of 81040266576 is 67566204018.

81040266576 is a `hidden beast` number, since 8 + 10 + 4 + 0 + 2 + 66 + 576 = 666.

It can be written as a sum of positive squares in only one way, i.e., 42097190976 + 38943075600 = 205176^2 + 197340^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 281389671 + ... + 281389958.

It is an arithmetic number, because the mean of its divisors is an integer number (7560006363).

Almost surely, 2^81040266576 is an apocalyptic number.

It is an amenable number.

81040266576 is an abundant number, since it is smaller than the sum of its proper divisors (145759924314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81040266576 is a wasteful number, since it uses less digits than its factorization.

81040266576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562779643 (or 562779634 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 81040266576 in words is "eighty-one billion, forty million, two hundred sixty-six thousand, five hundred seventy-six".