81918276 has 48 divisors (see below), whose sum is σ = 209744640. Its totient is φ = 24677920.

The previous prime is 81918251. The next prime is 81918281. The reversal of 81918276 is 67281918.

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, 21895 + ... + 25361.

It is an arithmetic number, because the mean of its divisors is an integer number (4369680).

Almost surely, 2^81918276 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 81918276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104872320).

81918276 is an abundant number, since it is smaller than the sum of its proper divisors (127826364).

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

81918276 is a wasteful number, since it uses less digits than its factorization.

81918276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3664 (or 3662 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 81918276 is about 9050.8715602421. The cubic root of 81918276 is about 434.3037719828.

The spelling of 81918276 in words is "eighty-one million, nine hundred eighteen thousand, two hundred seventy-six".