420191 has 2 divisors, whose sum is σ = 420192. Its totient is φ = 420190.

The previous prime is 420163. The next prime is 420193. The reversal of 420191 is 191024.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 420191 - 2¹⁸ = 158047 is a prime.

Together with 420193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210095 + 210096.

It is an arithmetic number, because the mean of its divisors is an integer number (210096).

2⁴²⁰¹⁹¹ is an apocalyptic number.

420191 is a deficient number, since it is larger than the sum of its proper divisors (1).

420191 is an equidigital number, since it uses as much as digits as its factorization.

420191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 420191 is about 648.2214127904. The cubic root of 420191 is about 74.9000743313.

The spelling of 420191 in words is "four hundred twenty thousand, one hundred ninety-one".