81109944 has 32 divisors (see below), whose sum is σ = 225306000. Its totient is φ = 27036576.

The previous prime is 81109939. The next prime is 81110023. The reversal of 81109944 is 44990118.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81109899 and 81109908.

It is a congruent number.

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, 187539 + ... + 187970.

Almost surely, 2^81109944 is an apocalyptic number.

It is an amenable number.

81109944 is an abundant number, since it is smaller than the sum of its proper divisors (144196056).

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

81109944 is a wasteful number, since it uses less digits than its factorization.

81109944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375524 (or 375514 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 81109944 is about 9006.1059287574. The cubic root of 81109944 is about 432.8705439295.

The spelling of 81109944 in words is "eighty-one million, one hundred nine thousand, nine hundred forty-four".