20147 has 2 divisors, whose sum is σ = 20148. Its totient is φ = 20146.

The previous prime is 20143. The next prime is 20149. The reversal of 20147 is 74102.

Added to its reverse (74102) it gives a square (94249 = 307²).

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20147 - 2² = 20143 is a prime.

Together with 20149, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20147.

It is not a weakly prime, because it can be changed into another prime (20143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10073 + 10074.

It is an arithmetic number, because the mean of its divisors is an integer number (10074).

2²⁰¹⁴⁷ is an apocalyptic number.

20147 is a deficient number, since it is larger than the sum of its proper divisors (1).

20147 is an equidigital number, since it uses as much as digits as its factorization.

20147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 20147 is about 141.9401282231. The cubic root of 20147 is about 27.2105171267.

Adding to 20147 its reverse (74102), we get a palindrome (94249).

The spelling of 20147 in words is "twenty thousand, one hundred forty-seven", and thus it is an iban number.