81072312 has 16 divisors (see below), whose sum is σ = 202680840. Its totient is φ = 27024096.

The previous prime is 81072307. The next prime is 81072323. The reversal of 81072312 is 21327018.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 3378013 = 81072312 / (8 + 1 + 0 + 7 + 2 + 3 + 1 + 2).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1688983 + ... + 1689030.

Almost surely, 2^81072312 is an apocalyptic number.

It is an amenable number.

81072312 is an abundant number, since it is smaller than the sum of its proper divisors (121608528).

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

81072312 is a wasteful number, since it uses less digits than its factorization.

81072312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3378022 (or 3378018 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 81072312 is about 9004.0164371240. The cubic root of 81072312 is about 432.8035882911.

The spelling of 81072312 in words is "eighty-one million, seventy-two thousand, three hundred twelve".