81359912 has 32 divisors (see below), whose sum is σ = 154751520. Its totient is φ = 40098240.

The previous prime is 81359899. The next prime is 81359917. The reversal of 81359912 is 21995318.

It is not an unprimeable number, because it can be changed into a prime (81359917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264863 + ... + 265169.

It is an arithmetic number, because the mean of its divisors is an integer number (4835985).

Almost surely, 2^81359912 is an apocalyptic number.

It is an amenable number.

81359912 is a deficient number, since it is larger than the sum of its proper divisors (73391608).

81359912 is a wasteful number, since it uses less digits than its factorization.

81359912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681 (or 677 counting only the distinct ones).

The product of its digits is 19440, while the sum is 38.

The square root of 81359912 is about 9019.9729489617. The cubic root of 81359912 is about 433.3147673834.

The spelling of 81359912 in words is "eighty-one million, three hundred fifty-nine thousand, nine hundred twelve".