81733880 has 48 divisors (see below), whose sum is σ = 187389720. Its totient is φ = 32084672.

The previous prime is 81733843. The next prime is 81733891. The reversal of 81733880 is 8833718.

It is a congruent number.

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, 138947 + ... + 139533.

Almost surely, 2^81733880 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 81733880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93694860).

81733880 is an abundant number, since it is smaller than the sum of its proper divisors (105655840).

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

81733880 is a wasteful number, since it uses less digits than its factorization.

81733880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716 (or 653 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 81733880 is about 9040.6791780264. The cubic root of 81733880 is about 433.9776581758.

The spelling of 81733880 in words is "eighty-one million, seven hundred thirty-three thousand, eight hundred eighty".