20839243 has 2 divisors, whose sum is σ = 20839244. Its totient is φ = 20839242.

The previous prime is 20839201. The next prime is 20839249. The reversal of 20839243 is 34293802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20839243 - 2¹³ = 20831051 is a prime.

It is not a weakly prime, because it can be changed into another prime (20839249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10419621 + 10419622.

It is an arithmetic number, because the mean of its divisors is an integer number (10419622).

Almost surely, 2^20839243 is an apocalyptic number.

20839243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20839243 is an equidigital number, since it uses as much as digits as its factorization.

20839243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 20839243 is about 4565.0019715220. The cubic root of 20839243 is about 275.1866193340.

The spelling of 20839243 in words is "twenty million, eight hundred thirty-nine thousand, two hundred forty-three".