81162279 has 24 divisors (see below), whose sum is σ = 130620672. Its totient is φ = 48139920.

The previous prime is 81162253. The next prime is 81162299. The reversal of 81162279 is 97226118.

It is not a de Polignac number, because 81162279 - 2⁹ = 81161767 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81162209) 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 23 ways as a sum of consecutive naturals, for example, 4069 + ... + 13374.

It is an arithmetic number, because the mean of its divisors is an integer number (5442528).

Almost surely, 2^81162279 is an apocalyptic number.

81162279 is a deficient number, since it is larger than the sum of its proper divisors (49458393).

81162279 is a wasteful number, since it uses less digits than its factorization.

81162279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17507 (or 17504 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 81162279 is about 9009.0109890043. The cubic root of 81162279 is about 432.9636250327.

The spelling of 81162279 in words is "eighty-one million, one hundred sixty-two thousand, two hundred seventy-nine".