20974189 has 2 divisors, whose sum is σ = 20974190. Its totient is φ = 20974188.

The previous prime is 20974171. The next prime is 20974193. The reversal of 20974189 is 98147902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19954089 + 1020100 = 4467^2 + 1010^2 .

It is a cyclic number.

It is not a de Polignac number, because 20974189 - 2¹¹ = 20972141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20974139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10487094 + 10487095.

It is an arithmetic number, because the mean of its divisors is an integer number (10487095).

Almost surely, 2^20974189 is an apocalyptic number.

It is an amenable number.

20974189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20974189 is an equidigital number, since it uses as much as digits as its factorization.

20974189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 20974189 is about 4579.7586180933. The cubic root of 20974189 is about 275.7793386116.

The spelling of 20974189 in words is "twenty million, nine hundred seventy-four thousand, one hundred eighty-nine".