81235812 has 48 divisors (see below), whose sum is σ = 217107072. Its totient is φ = 23159040.

The previous prime is 81235789. The next prime is 81235829. The reversal of 81235812 is 21853218.

It is a self number, because there is not a number n which added to its sum of digits gives 81235812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54112 + ... + 55592.

It is an arithmetic number, because the mean of its divisors is an integer number (4523064).

Almost surely, 2^81235812 is an apocalyptic number.

It is an amenable number.

81235812 is an abundant number, since it is smaller than the sum of its proper divisors (135871260).

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

81235812 is a wasteful number, since it uses less digits than its factorization.

81235812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2148 (or 2146 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 81235812 is about 9013.0911456614. The cubic root of 81235812 is about 433.0943405353.

The spelling of 81235812 in words is "eighty-one million, two hundred thirty-five thousand, eight hundred twelve".