81044406 has 72 divisors (see below), whose sum is σ = 191940840. Its totient is φ = 24621696.

The previous prime is 81044401. The next prime is 81044449. The reversal of 81044406 is 60444018.

It is a self number, because there is not a number n which added to its sum of digits gives 81044406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81044401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1209585 + ... + 1209651.

It is an arithmetic number, because the mean of its divisors is an integer number (2665845).

Almost surely, 2^81044406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81044406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95970420).

81044406 is an abundant number, since it is smaller than the sum of its proper divisors (110896434).

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

81044406 is a wasteful number, since it uses less digits than its factorization.

81044406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 81044406 is about 9002.4666619766. The cubic root of 81044406 is about 432.7539239742.

The spelling of 81044406 in words is "eighty-one million, forty-four thousand, four hundred six".