20426191 has 2 divisors, whose sum is σ = 20426192. Its totient is φ = 20426190.

The previous prime is 20426173. The next prime is 20426201. The reversal of 20426191 is 19162402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20426191 - 2¹¹ = 20424143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20426111) 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, 10213095 + 10213096.

It is an arithmetic number, because the mean of its divisors is an integer number (10213096).

Almost surely, 2^20426191 is an apocalyptic number.

20426191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20426191 is an equidigital number, since it uses as much as digits as its factorization.

20426191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 20426191 is about 4519.5343786722. The cubic root of 20426191 is about 273.3563264747.

Adding to 20426191 its reverse (19162402), we get a palindrome (39588593).

The spelling of 20426191 in words is "twenty million, four hundred twenty-six thousand, one hundred ninety-one".