20939459 has 2 divisors, whose sum is σ = 20939460. Its totient is φ = 20939458.

The previous prime is 20939419. The next prime is 20939473. The reversal of 20939459 is 95493902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20939459 - 2⁸ = 20939203 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20939419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10469729 + 10469730.

It is an arithmetic number, because the mean of its divisors is an integer number (10469730).

Almost surely, 2^20939459 is an apocalyptic number.

20939459 is a deficient number, since it is larger than the sum of its proper divisors (1).

20939459 is an equidigital number, since it uses as much as digits as its factorization.

20939459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 41.

The square root of 20939459 is about 4575.9653626311. The cubic root of 20939459 is about 275.6270385988.

The spelling of 20939459 in words is "twenty million, nine hundred thirty-nine thousand, four hundred fifty-nine".