81984276 has 144 divisors (see below), whose sum is σ = 239803200. Its totient is φ = 23580480.

The previous prime is 81984271. The next prime is 81984283. The reversal of 81984276 is 67248918.

It is a super-2 number, since 2×81984276² = 13442843022488352, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81984271) 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, 1389535 + ... + 1389593.

It is an arithmetic number, because the mean of its divisors is an integer number (1665300).

Almost surely, 2^81984276 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 81984276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119901600).

81984276 is an abundant number, since it is smaller than the sum of its proper divisors (157818924).

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

81984276 is a wasteful number, since it uses less digits than its factorization.

81984276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 104 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 81984276 is about 9054.5168838542. The cubic root of 81984276 is about 434.4203774412.

It can be divided in two parts, 819842 and 76, that added together give a palindrome (819918).

The spelling of 81984276 in words is "eighty-one million, nine hundred eighty-four thousand, two hundred seventy-six".