81326736 has 60 divisors (see below), whose sum is σ = 229445632. Its totient is φ = 26889408.

The previous prime is 81326699. The next prime is 81326743. The reversal of 81326736 is 63762318.

It is a happy number.

It is a super-2 number, since 2×81326736² = 13228075976827392, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81326736.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16065 + ... + 20511.

Almost surely, 2^81326736 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 81326736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114722816).

81326736 is an abundant number, since it is smaller than the sum of its proper divisors (148118896).

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

81326736 is a wasteful number, since it uses less digits than its factorization.

81326736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4588 (or 4579 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 81326736 is about 9018.1337315434. The cubic root of 81326736 is about 433.2558620216.

The spelling of 81326736 in words is "eighty-one million, three hundred twenty-six thousand, seven hundred thirty-six".