81522732672 has 96 divisors (see below), whose sum is σ = 240045886080. Its totient is φ = 26542268928.

The previous prime is 81522732649. The next prime is 81522732689. The reversal of 81522732672 is 27623722518.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 773328 + ... + 872399.

It is an arithmetic number, because the mean of its divisors is an integer number (2500477980).

Almost surely, 2^81522732672 is an apocalyptic number.

It is an amenable number.

81522732672 is an abundant number, since it is smaller than the sum of its proper divisors (158523153408).

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

81522732672 is a wasteful number, since it uses less digits than its factorization.

81522732672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645790 (or 1645775 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The spelling of 81522732672 in words is "eighty-one billion, five hundred twenty-two million, seven hundred thirty-two thousand, six hundred seventy-two".