20438189 has 2 divisors, whose sum is σ = 20438190. Its totient is φ = 20438188.

The previous prime is 20438183. The next prime is 20438203. The reversal of 20438189 is 98183402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10465225 + 9972964 = 3235^2 + 3158^2 .

It is a cyclic number.

It is not a de Polignac number, because 20438189 - 2⁸ = 20437933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20438183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219094 + 10219095.

It is an arithmetic number, because the mean of its divisors is an integer number (10219095).

Almost surely, 2^20438189 is an apocalyptic number.

It is an amenable number.

20438189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20438189 is an equidigital number, since it uses as much as digits as its factorization.

20438189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 20438189 is about 4520.8615329382. The cubic root of 20438189 is about 273.4098376305.

The spelling of 20438189 in words is "twenty million, four hundred thirty-eight thousand, one hundred eighty-nine".