81266864 has 20 divisors (see below), whose sum is σ = 179948304. Its totient is φ = 34828608.

The previous prime is 81266849. The next prime is 81266881. The reversal of 81266864 is 46866218.

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, 362687 + ... + 362910.

Almost surely, 2^81266864 is an apocalyptic number.

It is an amenable number.

81266864 is an abundant number, since it is smaller than the sum of its proper divisors (98681440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81266864 is a wasteful number, since it uses less digits than its factorization.

81266864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725612 (or 725606 counting only the distinct ones).

The product of its digits is 110592, while the sum is 41.

The square root of 81266864 is about 9014.8135865363. The cubic root of 81266864 is about 433.1495162514.

It can be divided in two parts, 812 and 66864, that added together give a palindrome (67676).

The spelling of 81266864 in words is "eighty-one million, two hundred sixty-six thousand, eight hundred sixty-four".