81256868 has 24 divisors (see below), whose sum is σ = 177288384. Its totient is φ = 31658400.

The previous prime is 81256867. The next prime is 81256883. The reversal of 81256868 is 86865218.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (81256867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131603 + ... + 132218.

It is an arithmetic number, because the mean of its divisors is an integer number (7387016).

Almost surely, 2^81256868 is an apocalyptic number.

It is an amenable number.

81256868 is an abundant number, since it is smaller than the sum of its proper divisors (96031516).

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

81256868 is a wasteful number, since it uses less digits than its factorization.

81256868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263843 (or 263841 counting only the distinct ones).

The product of its digits is 184320, while the sum is 44.

The square root of 81256868 is about 9014.2591487043. The cubic root of 81256868 is about 433.1317560808.

The spelling of 81256868 in words is "eighty-one million, two hundred fifty-six thousand, eight hundred sixty-eight".