81280896 has 64 divisors (see below), whose sum is σ = 225313920. Its totient is φ = 25912832.

The previous prime is 81280891. The next prime is 81280909. The reversal of 81280896 is 69808218.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81280891) 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, 4231 + ... + 13433.

It is an arithmetic number, because the mean of its divisors is an integer number (3520530).

Almost surely, 2^81280896 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 81280896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112656960).

81280896 is an abundant number, since it is smaller than the sum of its proper divisors (144033024).

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

81280896 is a wasteful number, since it uses less digits than its factorization.

81280896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9243 (or 9231 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 81280896 is about 9015.5918274953. The cubic root of 81280896 is about 433.1744448382.

The spelling of 81280896 in words is "eighty-one million, two hundred eighty thousand, eight hundred ninety-six".