81544512 has 224 divisors, whose sum is σ = 270369792. Its totient is φ = 21159936.

The previous prime is 81544501. The next prime is 81544579. The reversal of 81544512 is 21544518.

It is a tau number, because it is divible by the number of its divisors (224).

It is a self number, because there is not a number n which added to its sum of digits gives 81544512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 982423 + ... + 982505.

It is an arithmetic number, because the mean of its divisors is an integer number (1207008).

Almost surely, 2^81544512 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 81544512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135184896).

81544512 is an abundant number, since it is smaller than the sum of its proper divisors (188825280).

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

81544512 is a wasteful number, since it uses less digits than its factorization.

81544512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 155 counting only the distinct ones).

The product of its digits is 6400, while the sum is 30.

The square root of 81544512 is about 9030.1999977852. The cubic root of 81544512 is about 433.6422402262.

The spelling of 81544512 in words is "eighty-one million, five hundred forty-four thousand, five hundred twelve".