81169056 has 36 divisors (see below), whose sum is σ = 230825322. Its totient is φ = 27056256.

The previous prime is 81169051. The next prime is 81169061. The reversal of 81169056 is 65096118.

It is an interprime number because it is at equal distance from previous prime (81169051) and next prime (81169061).

It can be written as a sum of positive squares in only one way, i.e., 79923600 + 1245456 = 8940^2 + 1116^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×81169056² = 13176831303862272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81169056.

It is not an unprimeable number, because it can be changed into a prime (81169051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 140631 + ... + 141206.

Almost surely, 2^81169056 is an apocalyptic number.

It is an amenable number.

81169056 is an abundant number, since it is smaller than the sum of its proper divisors (149656266).

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

81169056 is a wasteful number, since it uses less digits than its factorization.

81169056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281853 (or 281842 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 81169056 is about 9009.3871045704. The cubic root of 81169056 is about 432.9756754288.

The spelling of 81169056 in words is "eighty-one million, one hundred sixty-nine thousand, fifty-six".