81884144 has 20 divisors (see below), whose sum is σ = 163769280. Its totient is φ = 39621120.

The previous prime is 81884141. The next prime is 81884147. The reversal of 81884144 is 44148818.

It is an interprime number because it is at equal distance from previous prime (81884141) and next prime (81884147).

81884144 is an admirable number.

It is a super-2 number, since 2×81884144² = 13410026077225472, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81884098 and 81884107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81884141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82049 + ... + 83040.

It is an arithmetic number, because the mean of its divisors is an integer number (8188464).

Almost surely, 2^81884144 is an apocalyptic number.

It is an amenable number.

81884144 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81884144 is a wasteful number, since it uses less digits than its factorization.

81884144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165128 (or 165122 counting only the distinct ones).

The product of its digits is 32768, while the sum is 38.

The square root of 81884144 is about 9048.9857995247. The cubic root of 81884144 is about 434.2434447219.

It can be divided in two parts, 81884 and 144, that added together give a palindrome (82028).

The spelling of 81884144 in words is "eighty-one million, eight hundred eighty-four thousand, one hundred forty-four".