81604312 has 16 divisors (see below), whose sum is σ = 155895840. Its totient is φ = 40032096.

The previous prime is 81604279. The next prime is 81604321. The reversal of 81604312 is 21340618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95808 + ... + 96655.

It is an arithmetic number, because the mean of its divisors is an integer number (9743490).

Almost surely, 2^81604312 is an apocalyptic number.

It is an amenable number.

81604312 is a deficient number, since it is larger than the sum of its proper divisors (74291528).

81604312 is a wasteful number, since it uses less digits than its factorization.

81604312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192522 (or 192518 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 81604312 is about 9033.5105025676. The cubic root of 81604312 is about 433.7482169864.

The spelling of 81604312 in words is "eighty-one million, six hundred four thousand, three hundred twelve".