81113205 has 48 divisors (see below), whose sum is σ = 142420032. Its totient is φ = 39283200.

The previous prime is 81113191. The next prime is 81113233. The reversal of 81113205 is 50231118.

It is not a de Polignac number, because 81113205 - 2¹⁰ = 81112181 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 244890 + ... + 245220.

It is an arithmetic number, because the mean of its divisors is an integer number (2967084).

Almost surely, 2^81113205 is an apocalyptic number.

81113205 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81113205 is a deficient number, since it is larger than the sum of its proper divisors (61306827).

81113205 is a wasteful number, since it uses less digits than its factorization.

81113205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 81113205 is about 9006.2869707777. The cubic root of 81113205 is about 432.8763449935.

It can be divided in two parts, 81113 and 205, that added together give a palindrome (81318).

The spelling of 81113205 in words is "eighty-one million, one hundred thirteen thousand, two hundred five".