81603165 has 16 divisors (see below), whose sum is σ = 149217408. Its totient is φ = 37304256.

The previous prime is 81603163. The next prime is 81603209. The reversal of 81603165 is 56130618.

It is not a de Polignac number, because 81603165 - 2¹ = 81603163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81603163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 388482 + ... + 388691.

It is an arithmetic number, because the mean of its divisors is an integer number (9326088).

Almost surely, 2^81603165 is an apocalyptic number.

It is an amenable number.

81603165 is a deficient number, since it is larger than the sum of its proper divisors (67614243).

81603165 is a wasteful number, since it uses less digits than its factorization.

81603165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777188.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81603165 is about 9033.4470165048. The cubic root of 81603165 is about 433.7461847754.

It can be divided in two parts, 8160 and 3165, that added together give a triangular number (11325 = T₁₅₀).

The spelling of 81603165 in words is "eighty-one million, six hundred three thousand, one hundred sixty-five".