1591 has 4 divisors (see below), whose sum is σ = 1672. Its totient is φ = 1512.

The previous prime is 1583. The next prime is 1597. The reversal of 1591 is 1951.

1591 is nontrivially palindromic in base 6.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1591 - 2³ = 1583 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 7, base 13 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16 + ... + 58.

It is an arithmetic number, because the mean of its divisors is an integer number (418).

2¹⁵⁹¹ is an apocalyptic number.

1591 is a deficient number, since it is larger than the sum of its proper divisors (81).

1591 is an equidigital number, since it uses as much as digits as its factorization.

1591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80.

The product of its digits is 45, while the sum is 16.

The square root of 1591 is about 39.8873413504. The cubic root of 1591 is about 11.6740995718.

The spelling of 1591 in words is "one thousand, five hundred ninety-one".