81868800 has 288 divisors, whose sum is σ = 298574640. Its totient is φ = 19660800.

The previous prime is 81868747. The next prime is 81868811. The reversal of 81868800 is 886818.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1996780 + ... + 1996820.

Almost surely, 2^81868800 is an apocalyptic number.

81868800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81868800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149287320).

81868800 is an abundant number, since it is smaller than the sum of its proper divisors (216705840).

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

81868800 is a wasteful number, since it uses less digits than its factorization.

81868800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 39.

The square root of 81868800 is about 9048.1379299832. The cubic root of 81868800 is about 434.2163192113.

The spelling of 81868800 in words is "eighty-one million, eight hundred sixty-eight thousand, eight hundred".