81038077072 has 20 divisors (see below), whose sum is σ = 158011351036. Its totient is φ = 40260954240.

The previous prime is 81038077067. The next prime is 81038077103. The reversal of 81038077072 is 27077083018.

It can be written as a sum of positive squares in 2 ways, for example, as 59576999056 + 21461078016 = 244084^2 + 146496^2 .

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, 16127679 + ... + 16132702.

Almost surely, 2^81038077072 is an apocalyptic number.

It is an amenable number.

81038077072 is a deficient number, since it is larger than the sum of its proper divisors (76973273964).

81038077072 is a wasteful number, since it uses less digits than its factorization.

81038077072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32260546 (or 32260540 counting only the distinct ones).

The product of its (nonzero) digits is 131712, while the sum is 43.

The spelling of 81038077072 in words is "eighty-one billion, thirty-eight million, seventy-seven thousand, seventy-two".