81788844 has 24 divisors (see below), whose sum is σ = 200885440. Its totient is φ = 25827984.

The previous prime is 81788831. The next prime is 81788867. The reversal of 81788844 is 44888718.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81788793 and 81788802.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179134 + ... + 179589.

Almost surely, 2^81788844 is an apocalyptic number.

It is an amenable number.

81788844 is an abundant number, since it is smaller than the sum of its proper divisors (119096596).

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

81788844 is a wasteful number, since it uses less digits than its factorization.

81788844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358749 (or 358747 counting only the distinct ones).

The product of its digits is 458752, while the sum is 48.

The square root of 81788844 is about 9043.7184830135. The cubic root of 81788844 is about 434.0749161025.

The spelling of 81788844 in words is "eighty-one million, seven hundred eighty-eight thousand, eight hundred forty-four".