81596544 has 64 divisors (see below), whose sum is σ = 222637440. Its totient is φ = 26459136.

The previous prime is 81596533. The next prime is 81596551. The reversal of 81596544 is 44569518.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 81596496 and 81596505.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11337 + ... + 17079.

It is an arithmetic number, because the mean of its divisors is an integer number (3478710).

Almost surely, 2^81596544 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 81596544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111318720).

81596544 is an abundant number, since it is smaller than the sum of its proper divisors (141040896).

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

81596544 is a wasteful number, since it uses less digits than its factorization.

81596544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5797 (or 5785 counting only the distinct ones).

The product of its digits is 172800, while the sum is 42.

The square root of 81596544 is about 9033.0805376682. The cubic root of 81596544 is about 433.7344535672.

The spelling of 81596544 in words is "eighty-one million, five hundred ninety-six thousand, five hundred forty-four".