20388191 has 2 divisors, whose sum is σ = 20388192. Its totient is φ = 20388190.

The previous prime is 20388161. The next prime is 20388211. The reversal of 20388191 is 19188302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20388191 - 2⁶ = 20388127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20388161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10194095 + 10194096.

It is an arithmetic number, because the mean of its divisors is an integer number (10194096).

Almost surely, 2^20388191 is an apocalyptic number.

20388191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20388191 is an equidigital number, since it uses as much as digits as its factorization.

20388191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 20388191 is about 4515.3284487399. The cubic root of 20388191 is about 273.1867078287.

The spelling of 20388191 in words is "twenty million, three hundred eighty-eight thousand, one hundred ninety-one".