81421675584 has 112 divisors (see below), whose sum is σ = 223622737920. Its totient is φ = 26117982720.

The previous prime is 81421675579. The next prime is 81421675591. The reversal of 81421675584 is 48557612418.

It is a happy number.

It is a super-2 number, since 2×81421675584² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1027197 + ... + 1103619.

Almost surely, 2^81421675584 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81421675584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111811368960).

81421675584 is an abundant number, since it is smaller than the sum of its proper divisors (142201062336).

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

81421675584 is a wasteful number, since it uses less digits than its factorization.

81421675584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76648 (or 76638 counting only the distinct ones).

The product of its digits is 2150400, while the sum is 51.

The spelling of 81421675584 in words is "eighty-one billion, four hundred twenty-one million, six hundred seventy-five thousand, five hundred eighty-four".