81200784 has 80 divisors (see below), whose sum is σ = 243381248. Its totient is φ = 22847616.

The previous prime is 81200731. The next prime is 81200797. The reversal of 81200784 is 48700218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20709 + ... + 24315.

Almost surely, 2^81200784 is an apocalyptic number.

81200784 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81200784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121690624).

81200784 is an abundant number, since it is smaller than the sum of its proper divisors (162180464).

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

81200784 is a wasteful number, since it uses less digits than its factorization.

81200784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3692 (or 3686 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 81200784 is about 9011.1477626327. The cubic root of 81200784 is about 433.0320830607.

The spelling of 81200784 in words is "eighty-one million, two hundred thousand, seven hundred eighty-four".