20693 has 2 divisors, whose sum is σ = 20694.
Its totient is φ = 20692.
The previous prime is 20681. The next prime is 20707. The reversal of 20693 is 39602.
It is a happy number.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 20164 + 529 = 142^2 + 23^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-20693 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a Curzon number.
It is a nialpdrome in base 12.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20663) 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, 10346 + 10347.
It is an arithmetic number, because the mean of its divisors is an integer number (10347).
220693 is an apocalyptic number.
It is an amenable number.
20693 is a deficient number, since it is larger than the sum of its proper divisors (1).
20693 is an equidigital number, since it uses as much as digits as its factorization.
20693 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 324, while the sum is 20.
The square root of 20693 is about 143.8506169608.
The cubic root of 20693 is about 27.4541384355.
The spelling of 20693 in words is "twenty thousand, six hundred ninety-three".