20105191 has 2 divisors, whose sum is σ = 20105192. Its totient is φ = 20105190.

The previous prime is 20105147. The next prime is 20105201. The reversal of 20105191 is 19150102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20105191 - 2¹¹ = 20103143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20105131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10052595 + 10052596.

It is an arithmetic number, because the mean of its divisors is an integer number (10052596).

Almost surely, 2^20105191 is an apocalyptic number.

20105191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20105191 is an equidigital number, since it uses as much as digits as its factorization.

20105191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90, while the sum is 19.

The square root of 20105191 is about 4483.8812428520. The cubic root of 20105191 is about 271.9168169439.

Adding to 20105191 its reverse (19150102), we get a palindrome (39255293).

The spelling of 20105191 in words is "twenty million, one hundred five thousand, one hundred ninety-one".