81168261 has 16 divisors (see below), whose sum is σ = 112035840. Its totient is φ = 52216560.

The previous prime is 81168259. The next prime is 81168271. The reversal of 81168261 is 16286118.

It is not a de Polignac number, because 81168261 - 2¹ = 81168259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81168211) 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 15 ways as a sum of consecutive naturals, for example, 37926 + ... + 40008.

It is an arithmetic number, because the mean of its divisors is an integer number (7002240).

Almost surely, 2^81168261 is an apocalyptic number.

It is an amenable number.

81168261 is a deficient number, since it is larger than the sum of its proper divisors (30867579).

81168261 is a wasteful number, since it uses less digits than its factorization.

81168261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2536.

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

The square root of 81168261 is about 9009.3429838141. The cubic root of 81168261 is about 432.9742618491.

The spelling of 81168261 in words is "eighty-one million, one hundred sixty-eight thousand, two hundred sixty-one".