81590 has 16 divisors (see below), whose sum is σ = 151200. Its totient is φ = 31680.

The previous prime is 81569. The next prime is 81611. The reversal of 81590 is 9518.

It is an interprime number because it is at equal distance from previous prime (81569) and next prime (81611).

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81590.

It is an unprimeable number.

81590 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 7 ways as a sum of consecutive naturals, for example, 311 + ... + 509.

It is an arithmetic number, because the mean of its divisors is an integer number (9450).

2⁸¹⁵⁹⁰ is an apocalyptic number.

81590 is a deficient number, since it is larger than the sum of its proper divisors (69610).

81590 is a wasteful number, since it uses less digits than its factorization.

81590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 81590 is about 285.6396331044. The cubic root of 81590 is about 43.3722858165.

It can be divided in two parts, 8 and 1590, that multiplied together give a triangular number (12720 = T₁₅₉).

The spelling of 81590 in words is "eighty-one thousand, five hundred ninety".