20249 has 2 divisors, whose sum is σ = 20250.
Its totient is φ = 20248.
The previous prime is 20233. The next prime is 20261. The reversal of 20249 is 94202.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 15625 + 4624 = 125^2 + 68^2
It is a cyclic number.
It is not a de Polignac number, because 20249 - 24 = 20233 is a prime.
It is a Sophie Germain prime.
It is a Curzon number.
It is a plaindrome in base 15.
It is a nialpdrome in base 12.
It is not a weakly prime, because it can be changed into another prime (20219) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10124 + 10125.
It is an arithmetic number, because the mean of its divisors is an integer number (10125).
220249 is an apocalyptic number.
It is an amenable number.
20249 is a deficient number, since it is larger than the sum of its proper divisors (1).
20249 is an equidigital number, since it uses as much as digits as its factorization.
20249 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 144, while the sum is 17.
The square root of 20249 is about 142.2989810224.
The cubic root of 20249 is about 27.2563602133.
The spelling of 20249 in words is "twenty thousand, two hundred forty-nine".