201220391 has 2 divisors, whose sum is σ = 201220392. Its totient is φ = 201220390.

The previous prime is 201220337. The next prime is 201220423. The reversal of 201220391 is 193022102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201220391 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201220321) 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, 100610195 + 100610196.

It is an arithmetic number, because the mean of its divisors is an integer number (100610196).

Almost surely, 2^201220391 is an apocalyptic number.

201220391 is a deficient number, since it is larger than the sum of its proper divisors (1).

201220391 is an equidigital number, since it uses as much as digits as its factorization.

201220391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 201220391 is about 14185.2173405979. The cubic root of 201220391 is about 585.9906180671.

Adding to 201220391 its reverse (193022102), we get a palindrome (394242493).

The spelling of 201220391 in words is "two hundred one million, two hundred twenty thousand, three hundred ninety-one".