81865363 has 4 divisors (see below), whose sum is σ = 81917488. Its totient is φ = 81813240.

The previous prime is 81865361. The next prime is 81865369. The reversal of 81865363 is 36356818.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81865363 - 2¹ = 81865361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81865361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23631 + ... + 26872.

It is an arithmetic number, because the mean of its divisors is an integer number (20479372).

Almost surely, 2^81865363 is an apocalyptic number.

81865363 is a deficient number, since it is larger than the sum of its proper divisors (52125).

81865363 is a wasteful number, since it uses less digits than its factorization.

81865363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52124.

The product of its digits is 103680, while the sum is 40.

The square root of 81865363 is about 9047.9479994085. The cubic root of 81865363 is about 434.2102427313.

It can be divided in two parts, 81865 and 363, that added together give a palindrome (82228).

The spelling of 81865363 in words is "eighty-one million, eight hundred sixty-five thousand, three hundred sixty-three".