81160225 has 12 divisors (see below), whose sum is σ = 102539196. Its totient is φ = 63702080.

The previous prime is 81160213. The next prime is 81160231. The reversal of 81160225 is 52206118.

It can be written as a sum of positive squares in 6 ways, for example, as 4999696 + 76160529 = 2236^2 + 8727^2 .

It is not a de Polignac number, because 81160225 - 2¹⁵ = 81127457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81160225.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 29302 + ... + 31951.

It is an arithmetic number, because the mean of its divisors is an integer number (8544933).

Almost surely, 2^81160225 is an apocalyptic number.

It is an amenable number.

81160225 is a deficient number, since it is larger than the sum of its proper divisors (21378971).

81160225 is a wasteful number, since it uses less digits than its factorization.

81160225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61316 (or 61311 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 81160225 is about 9008.8969913081. The cubic root of 81160225 is about 432.9599726185.

The spelling of 81160225 in words is "eighty-one million, one hundred sixty thousand, two hundred twenty-five".