20438389 has 2 divisors, whose sum is σ = 20438390. Its totient is φ = 20438388.

The previous prime is 20438387. The next prime is 20438413. The reversal of 20438389 is 98383402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16337764 + 4100625 = 4042^2 + 2025^2 .

It is a cyclic number.

It is not a de Polignac number, because 20438389 - 2¹ = 20438387 is a prime.

Together with 20438387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20438387) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219194 + 10219195.

It is an arithmetic number, because the mean of its divisors is an integer number (10219195).

Almost surely, 2^20438389 is an apocalyptic number.

It is an amenable number.

20438389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20438389 is an equidigital number, since it uses as much as digits as its factorization.

20438389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 20438389 is about 4520.8836525617. The cubic root of 20438389 is about 273.4107294543.

The spelling of 20438389 in words is "twenty million, four hundred thirty-eight thousand, three hundred eighty-nine".