81040736 has 24 divisors (see below), whose sum is σ = 182342160. Its totient is φ = 34731648.

The previous prime is 81040711. The next prime is 81040747. The reversal of 81040736 is 63704018.

It is a junction number, because it is equal to n+sod(n) for n = 81040699 and 81040708.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180671 + ... + 181118.

It is an arithmetic number, because the mean of its divisors is an integer number (7597590).

Almost surely, 2^81040736 is an apocalyptic number.

It is an amenable number.

81040736 is an abundant number, since it is smaller than the sum of its proper divisors (101301424).

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

81040736 is a wasteful number, since it uses less digits than its factorization.

81040736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361806 (or 361798 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 81040736 is about 9002.2628266453. The cubic root of 81040736 is about 432.7473916259.

The spelling of 81040736 in words is "eighty-one million, forty thousand, seven hundred thirty-six".