20743 has 2 divisors, whose sum is σ = 20744. Its totient is φ = 20742.

The previous prime is 20731. The next prime is 20747. The reversal of 20743 is 34702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20743 - 2⁹ = 20231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20747) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10371 + 10372.

It is an arithmetic number, because the mean of its divisors is an integer number (10372).

2²⁰⁷⁴³ is an apocalyptic number.

20743 is a deficient number, since it is larger than the sum of its proper divisors (1).

20743 is an equidigital number, since it uses as much as digits as its factorization.

20743 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 16.

The square root of 20743 is about 144.0243035047. The cubic root of 20743 is about 27.4762329085.

The spelling of 20743 in words is "twenty thousand, seven hundred forty-three", and thus it is an iban number.