81040336 has 40 divisors (see below), whose sum is σ = 170371040. Its totient is φ = 37120896.

The previous prime is 81040331. The next prime is 81040369. The reversal of 81040336 is 63304018.

It is a self number, because there is not a number n which added to its sum of digits gives 81040336.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81040331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27511 + ... + 30313.

It is an arithmetic number, because the mean of its divisors is an integer number (4259276).

Almost surely, 2^81040336 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 81040336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85185520).

81040336 is an abundant number, since it is smaller than the sum of its proper divisors (89330704).

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

81040336 is a wasteful number, since it uses less digits than its factorization.

81040336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2963 (or 2957 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 81040336 is about 9002.2406099815. The cubic root of 81040336 is about 432.7466796414.

The spelling of 81040336 in words is "eighty-one million, forty thousand, three hundred thirty-six".