81288800 has 36 divisors (see below), whose sum is σ = 198448236. Its totient is φ = 32515200.

The previous prime is 81288799. The next prime is 81288811. The reversal of 81288800 is 888218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50006 + ... + 51605.

It is an arithmetic number, because the mean of its divisors is an integer number (5512451).

Almost surely, 2^81288800 is an apocalyptic number.

81288800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81288800 is an abundant number, since it is smaller than the sum of its proper divisors (117159436).

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

81288800 is a wasteful number, since it uses less digits than its factorization.

81288800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101631 (or 101618 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 35.

The square root of 81288800 is about 9016.0301685387. The cubic root of 81288800 is about 433.1884854472.

The spelling of 81288800 in words is "eighty-one million, two hundred eighty-eight thousand, eight hundred".