81289584 has 60 divisors (see below), whose sum is σ = 229629400. Its totient is φ = 26842752.

The previous prime is 81289577. The next prime is 81289591. The reversal of 81289584 is 48598218.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81289577) and next prime (81289591).

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 11 ways as a sum of consecutive naturals, for example, 13107 + ... + 18285.

Almost surely, 2^81289584 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 81289584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114814700).

81289584 is an abundant number, since it is smaller than the sum of its proper divisors (148339816).

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

81289584 is a wasteful number, since it uses less digits than its factorization.

81289584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302 (or 5293 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 81289584 is about 9016.0736465493. The cubic root of 81289584 is about 433.1898780896.

The spelling of 81289584 in words is "eighty-one million, two hundred eighty-nine thousand, five hundred eighty-four".