81822312 has 160 divisors (see below), whose sum is σ = 269549280. Its totient is φ = 22861440.

The previous prime is 81822271. The next prime is 81822337. The reversal of 81822312 is 21322818.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 92223 + ... + 93105.

It is an arithmetic number, because the mean of its divisors is an integer number (1684683).

Almost surely, 2^81822312 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 81822312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134774640).

81822312 is an abundant number, since it is smaller than the sum of its proper divisors (187726968).

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

81822312 is a wasteful number, since it uses less digits than its factorization.

81822312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925 (or 912 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 81822312 is about 9045.5686388419. The cubic root of 81822312 is about 434.1341158558.

The spelling of 81822312 in words is "eighty-one million, eight hundred twenty-two thousand, three hundred twelve".