81288791232 has 336 divisors, whose sum is σ = 245183997312. Its totient is φ = 23766336000.

The previous prime is 81288791219. The next prime is 81288791237. The reversal of 81288791232 is 23219788218.

Its product of digits (774144) is a multiple of the sum of its prime divisors (378).

It is not an unprimeable number, because it can be changed into a prime (81288791237) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 245585307 + ... + 245585637.

Almost surely, 2^81288791232 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 81288791232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122591998656).

81288791232 is an abundant number, since it is smaller than the sum of its proper divisors (163895206080).

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

81288791232 is a wasteful number, since it uses less digits than its factorization.

81288791232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 378 counting only the distinct ones).

The product of its digits is 774144, while the sum is 51.

The spelling of 81288791232 in words is "eighty-one billion, two hundred eighty-eight million, seven hundred ninety-one thousand, two hundred thirty-two".