81998336112 has 320 divisors, whose sum is σ = 280501761024. Its totient is φ = 19983237120.

The previous prime is 81998336053. The next prime is 81998336131. The reversal of 81998336112 is 21163389918.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 22177848 + ... + 22181544.

Almost surely, 2^81998336112 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 81998336112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140250880512).

81998336112 is an abundant number, since it is smaller than the sum of its proper divisors (198503424912).

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

81998336112 is a wasteful number, since it uses less digits than its factorization.

81998336112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4096 (or 4090 counting only the distinct ones).

The product of its digits is 559872, while the sum is 51.

The spelling of 81998336112 in words is "eighty-one billion, nine hundred ninety-eight million, three hundred thirty-six thousand, one hundred twelve".