81988200 has 288 divisors, whose sum is σ = 327687360. Its totient is φ = 18662400.

The previous prime is 81988171. The next prime is 81988219. The reversal of 81988200 is 288918.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 340080 + ... + 340320.

Almost surely, 2^81988200 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 81988200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163843680).

81988200 is an abundant number, since it is smaller than the sum of its proper divisors (245699160).

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

81988200 is a wasteful number, since it uses less digits than its factorization.

81988200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 81988200 is about 9054.7335686921. The cubic root of 81988200 is about 434.4273081944.

The spelling of 81988200 in words is "eighty-one million, nine hundred eighty-eight thousand, two hundred".