20320439 has 2 divisors, whose sum is σ = 20320440. Its totient is φ = 20320438.

The previous prime is 20320427. The next prime is 20320441. The reversal of 20320439 is 93402302.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20320439 is a prime.

It is a Sophie Germain prime.

Together with 20320441, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20320409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160219 + 10160220.

It is an arithmetic number, because the mean of its divisors is an integer number (10160220).

Almost surely, 2^20320439 is an apocalyptic number.

20320439 is a deficient number, since it is larger than the sum of its proper divisors (1).

20320439 is an equidigital number, since it uses as much as digits as its factorization.

20320439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 20320439 is about 4507.8197612593. The cubic root of 20320439 is about 272.8837630812.

The spelling of 20320439 in words is "twenty million, three hundred twenty thousand, four hundred thirty-nine".