20012191 has 2 divisors, whose sum is σ = 20012192. Its totient is φ = 20012190.

The previous prime is 20012189. The next prime is 20012203. The reversal of 20012191 is 19121002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20012191 - 2¹ = 20012189 is a prime.

Together with 20012189, 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 (20012101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006095 + 10006096.

It is an arithmetic number, because the mean of its divisors is an integer number (10006096).

Almost surely, 2^20012191 is an apocalyptic number.

20012191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012191 is an equidigital number, since it uses as much as digits as its factorization.

20012191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 20012191 is about 4473.4987425951. The cubic root of 20012191 is about 271.4969028992.

Adding to 20012191 its reverse (19121002), we get a palindrome (39133193).

The spelling of 20012191 in words is "twenty million, twelve thousand, one hundred ninety-one".