81461718072 has 96 divisors (see below), whose sum is σ = 258958159200. Its totient is φ = 22645723392.

The previous prime is 81461718049. The next prime is 81461718083. The reversal of 81461718072 is 27081716418.

81461718072 is a `hidden beast` number, since 8 + 1 + 461 + 7 + 180 + 7 + 2 = 666.

It is a super-2 number, since 2×81461718072² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2165547 + ... + 2202842.

It is an arithmetic number, because the mean of its divisors is an integer number (2697480825).

Almost surely, 2^81461718072 is an apocalyptic number.

It is an amenable number.

81461718072 is an abundant number, since it is smaller than the sum of its proper divisors (177496441128).

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

81461718072 is a wasteful number, since it uses less digits than its factorization.

81461718072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4368445 (or 4368438 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 45.

The spelling of 81461718072 in words is "eighty-one billion, four hundred sixty-one million, seven hundred eighteen thousand, seventy-two".