81806470200 has 432 divisors, whose sum is σ = 344176330680. Its totient is φ = 17260024320.

The previous prime is 81806470199. The next prime is 81806470309. The reversal of 81806470200 is 207460818.

81806470200 is a `hidden beast` number, since 8 + 1 + 8 + 0 + 647 + 0 + 2 + 0 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1110927 + ... + 1182273.

Almost surely, 2^81806470200 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 81806470200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172088165340).

81806470200 is an abundant number, since it is smaller than the sum of its proper divisors (262369860480).

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

81806470200 is a wasteful number, since it uses less digits than its factorization.

81806470200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71396 (or 71377 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 81806470200 in words is "eighty-one billion, eight hundred six million, four hundred seventy thousand, two hundred".