81998395200 has 336 divisors, whose sum is σ = 300944280000. Its totient is φ = 21717780480.

The previous prime is 81998395177. The next prime is 81998395217. The reversal of 81998395200 is 259389918.

81998395200 is a `hidden beast` number, since 81 + 9 + 9 + 8 + 39 + 520 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6430431 + ... + 6443169.

It is an arithmetic number, because the mean of its divisors is an integer number (895667500).

Almost surely, 2^81998395200 is an apocalyptic number.

81998395200 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 81998395200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150472140000).

81998395200 is an abundant number, since it is smaller than the sum of its proper divisors (218945884800).

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

81998395200 is a wasteful number, since it uses less digits than its factorization.

81998395200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12919 (or 12898 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 81998395200 in words is "eighty-one billion, nine hundred ninety-eight million, three hundred ninety-five thousand, two hundred".