81867312 has 30 divisors (see below), whose sum is σ = 229115172. Its totient is φ = 27289056.

The previous prime is 81867301. The next prime is 81867343. The reversal of 81867312 is 21376818.

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

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 284118 + ... + 284405.

Almost surely, 2^81867312 is an apocalyptic number.

It is an amenable number.

81867312 is an abundant number, since it is smaller than the sum of its proper divisors (147247860).

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

81867312 is a wasteful number, since it uses less digits than its factorization.

81867312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568537 (or 568528 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 81867312 is about 9048.0557027463. The cubic root of 81867312 is about 434.2136885071.

The spelling of 81867312 in words is "eighty-one million, eight hundred sixty-seven thousand, three hundred twelve".