81600165 has 12 divisors (see below), whose sum is σ = 141440364. Its totient is φ = 43520064.

The previous prime is 81600163. The next prime is 81600263. The reversal of 81600165 is 56100618.

It can be written as a sum of positive squares in 2 ways, for example, as 47692836 + 33907329 = 6906^2 + 5823^2 .

It is not a de Polignac number, because 81600165 - 2¹ = 81600163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81600161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 906624 + ... + 906713.

It is an arithmetic number, because the mean of its divisors is an integer number (11786697).

Almost surely, 2^81600165 is an apocalyptic number.

It is an amenable number.

81600165 is a deficient number, since it is larger than the sum of its proper divisors (59840199).

81600165 is a wasteful number, since it uses less digits than its factorization.

81600165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1813348 (or 1813345 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 81600165 is about 9033.2809654079. The cubic root of 81600165 is about 433.7408693995.

The spelling of 81600165 in words is "eighty-one million, six hundred thousand, one hundred sixty-five".