81155792 has 20 divisors (see below), whose sum is σ = 160897440. Its totient is φ = 39633888.

The previous prime is 81155791. The next prime is 81155797. The reversal of 81155792 is 29755118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81155791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58292 + ... + 59667.

It is an arithmetic number, because the mean of its divisors is an integer number (8044872).

Almost surely, 2^81155792 is an apocalyptic number.

It is an amenable number.

81155792 is a deficient number, since it is larger than the sum of its proper divisors (79741648).

81155792 is a wasteful number, since it uses less digits than its factorization.

81155792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118010 (or 118004 counting only the distinct ones).

The product of its digits is 25200, while the sum is 38.

The square root of 81155792 is about 9008.6509533892. The cubic root of 81155792 is about 432.9520896664.

The spelling of 81155792 in words is "eighty-one million, one hundred fifty-five thousand, seven hundred ninety-two".