81161268 has 24 divisors (see below), whose sum is σ = 189538272. Its totient is φ = 27030624.

The previous prime is 81161261. The next prime is 81161279. The reversal of 81161268 is 86216118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81161261) 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 7 ways as a sum of consecutive naturals, for example, 17446 + ... + 21602.

It is an arithmetic number, because the mean of its divisors is an integer number (7897428).

Almost surely, 2^81161268 is an apocalyptic number.

It is an amenable number.

81161268 is an abundant number, since it is smaller than the sum of its proper divisors (108377004).

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

81161268 is a wasteful number, since it uses less digits than its factorization.

81161268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5791 (or 5789 counting only the distinct ones).

The product of its digits is 4608, while the sum is 33.

The square root of 81161268 is about 9008.9548783419. The cubic root of 81161268 is about 432.9618272845.

The spelling of 81161268 in words is "eighty-one million, one hundred sixty-one thousand, two hundred sixty-eight".