81589086 has 128 divisors (see below), whose sum is σ = 205701120. Its totient is φ = 23846400.

The previous prime is 81589063. The next prime is 81589111. The reversal of 81589086 is 68098518.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1337496 + ... + 1337556.

It is an arithmetic number, because the mean of its divisors is an integer number (1607040).

Almost surely, 2^81589086 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81589086, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102850560).

81589086 is an abundant number, since it is smaller than the sum of its proper divisors (124112034).

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

81589086 is a wasteful number, since it uses less digits than its factorization.

81589086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 81589086 is about 9032.6677122542. The cubic root of 81589086 is about 433.7212385871.

The spelling of 81589086 in words is "eighty-one million, five hundred eighty-nine thousand, eighty-six".