81895800 has 384 divisors, whose sum is σ = 325693440. Its totient is φ = 16588800.

The previous prime is 81895789. The next prime is 81895813. The reversal of 81895800 is 859818.

81895800 = 238² + 239² + ... + 637².

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2213382 + ... + 2213418.

It is an arithmetic number, because the mean of its divisors is an integer number (848160).

Almost surely, 2^81895800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81895800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162846720).

81895800 is an abundant number, since it is smaller than the sum of its proper divisors (243797640).

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

81895800 is a wasteful number, since it uses less digits than its factorization.

81895800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 39.

The square root of 81895800 is about 9049.6298266835. The cubic root of 81895800 is about 434.2640482282.

The spelling of 81895800 in words is "eighty-one million, eight hundred ninety-five thousand, eight hundred".