81798336 has 140 divisors (see below), whose sum is σ = 250789440. Its totient is φ = 26334720.

The previous prime is 81798331. The next prime is 81798337. The reversal of 81798336 is 63389718.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81798291 and 81798300.

It is not an unprimeable number, because it can be changed into a prime (81798331) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 160450 + ... + 160958.

Almost surely, 2^81798336 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 81798336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125394720).

81798336 is an abundant number, since it is smaller than the sum of its proper divisors (168991104).

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

81798336 is a wasteful number, since it uses less digits than its factorization.

81798336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564 (or 545 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 81798336 is about 9044.2432519255. The cubic root of 81798336 is about 434.0917076335.

The spelling of 81798336 in words is "eighty-one million, seven hundred ninety-eight thousand, three hundred thirty-six".