81914784 has 96 divisors (see below), whose sum is σ = 249016320. Its totient is φ = 23092992.

The previous prime is 81914779. The next prime is 81914831. The reversal of 81914784 is 48741918.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52317 + ... + 53859.

It is an arithmetic number, because the mean of its divisors is an integer number (2593920).

Almost surely, 2^81914784 is an apocalyptic number.

81914784 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 81914784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124508160).

81914784 is an abundant number, since it is smaller than the sum of its proper divisors (167101536).

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

81914784 is a wasteful number, since it uses less digits than its factorization.

81914784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1642 (or 1634 counting only the distinct ones).

The product of its digits is 64512, while the sum is 42.

The square root of 81914784 is about 9050.6786485876. The cubic root of 81914784 is about 434.2976007497.

The spelling of 81914784 in words is "eighty-one million, nine hundred fourteen thousand, seven hundred eighty-four".