139591 has 2 divisors, whose sum is σ = 139592. Its totient is φ = 139590.

The previous prime is 139589. The next prime is 139597. The reversal of 139591 is 195931.

It is a weak prime.

It is an emirp because it is prime and its reverse (195931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139591 - 2¹ = 139589 is a prime.

Together with 139589, it forms a pair of twin primes.

139591 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139597) 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 as a sum of consecutive naturals, namely, 69795 + 69796.

It is an arithmetic number, because the mean of its divisors is an integer number (69796).

2¹³⁹⁵⁹¹ is an apocalyptic number.

139591 is a deficient number, since it is larger than the sum of its proper divisors (1).

139591 is an equidigital number, since it uses as much as digits as its factorization.

139591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1215, while the sum is 28.

The square root of 139591 is about 373.6187896774. The cubic root of 139591 is about 51.8743266957.

It can be divided in two parts, 13 and 9591, that added together give a square (9604 = 98²).

The spelling of 139591 in words is "one hundred thirty-nine thousand, five hundred ninety-one".