81793872 has 120 divisors (see below), whose sum is σ = 240484608. Its totient is φ = 25920000.

The previous prime is 81793867. The next prime is 81793897. The reversal of 81793872 is 27839718.

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, 325747 + ... + 325997.

Almost surely, 2^81793872 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 81793872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120242304).

81793872 is an abundant number, since it is smaller than the sum of its proper divisors (158690736).

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

81793872 is a wasteful number, since it uses less digits than its factorization.

81793872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 360 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 81793872 is about 9043.9964617419. The cubic root of 81793872 is about 434.0838108932.

The spelling of 81793872 in words is "eighty-one million, seven hundred ninety-three thousand, eight hundred seventy-two".