81736568 has 16 divisors (see below), whose sum is σ = 153360000. Its totient is φ = 40840576.

The previous prime is 81736559. The next prime is 81736579. The reversal of 81736568 is 86563718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14633 + ... + 19431.

It is an arithmetic number, because the mean of its divisors is an integer number (9585000).

Almost surely, 2^81736568 is an apocalyptic number.

It is an amenable number.

81736568 is a deficient number, since it is larger than the sum of its proper divisors (71623432).

81736568 is a wasteful number, since it uses less digits than its factorization.

81736568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6934 (or 6930 counting only the distinct ones).

The product of its digits is 241920, while the sum is 44.

The square root of 81736568 is about 9040.8278382015. The cubic root of 81736568 is about 433.9824155631.

It can be divided in two parts, 8173 and 6568, that added together give a palindrome (14741).

The spelling of 81736568 in words is "eighty-one million, seven hundred thirty-six thousand, five hundred sixty-eight".