20331191 has 2 divisors, whose sum is σ = 20331192. Its totient is φ = 20331190.

The previous prime is 20331161. The next prime is 20331209. The reversal of 20331191 is 19113302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20331191 - 2⁶ = 20331127 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20331151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10165595 + 10165596.

It is an arithmetic number, because the mean of its divisors is an integer number (10165596).

Almost surely, 2^20331191 is an apocalyptic number.

20331191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20331191 is an equidigital number, since it uses as much as digits as its factorization.

20331191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 20331191 is about 4509.0121978101. The cubic root of 20331191 is about 272.9318842346.

Adding to 20331191 its reverse (19113302), we get a palindrome (39444493).

The spelling of 20331191 in words is "twenty million, three hundred thirty-one thousand, one hundred ninety-one".