81461072549572 has 24 divisors (see below), whose sum is σ = 145169270215200. Its totient is φ = 39986006535936.

The previous prime is 81461072549569. The next prime is 81461072549639. The reversal of 81461072549572 is 27594527016418.

It is a self number, because there is not a number n which added to its sum of digits gives 81461072549572.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233366893 + ... + 233715700.

It is an arithmetic number, because the mean of its divisors is an integer number (6048719592300).

Almost surely, 2^{81461072549572} is an apocalyptic number.

It is an amenable number.

81461072549572 is a deficient number, since it is larger than the sum of its proper divisors (63708197665628).

81461072549572 is a wasteful number, since it uses less digits than its factorization.

81461072549572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467083395 (or 467083393 counting only the distinct ones).

The product of its (nonzero) digits is 33868800, while the sum is 61.

The spelling of 81461072549572 in words is "eighty-one trillion, four hundred sixty-one billion, seventy-two million, five hundred forty-nine thousand, five hundred seventy-two".