19391 has 2 divisors, whose sum is σ = 19392. Its totient is φ = 19390.
The previous prime is 19387. The next prime is 19403.
19391 is nontrivially palindromic in base 10.
It is a weak prime.
It is a palprime.
It is a cyclic number.
It is not a de Polignac number, because 19391 - 22 = 19387 is a prime.
It is a Sophie Germain prime.
It is a plaindrome in base 8 and base 16.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (19301) by changing a digit.
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 as a sum of consecutive naturals, namely, 9695 + 9696.
It is an arithmetic number, because the mean of its divisors is an integer number (9696).
219391 is an apocalyptic number.
19391 is a deficient number, since it is larger than the sum of its proper divisors (1).
19391 is an equidigital number, since it uses as much as digits as its factorization.
19391 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 243, while the sum is 23.
The square root of 19391 is about 139.2515709068. The cubic root of 19391 is about 26.8658180279.
The spelling of 19391 in words is "nineteen thousand, three hundred ninety-one".
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.070 sec. • engine limits •