421212191 has 2 divisors, whose sum is σ = 421212192. Its totient is φ = 421212190.

The previous prime is 421212173. The next prime is 421212199. The reversal of 421212191 is 191212124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 421212191 - 2²⁶ = 354103327 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421212199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210606095 + 210606096.

It is an arithmetic number, because the mean of its divisors is an integer number (210606096).

Almost surely, 2^421212191 is an apocalyptic number.

421212191 is a deficient number, since it is larger than the sum of its proper divisors (1).

421212191 is an equidigital number, since it uses as much as digits as its factorization.

421212191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 23.

The square root of 421212191 is about 20523.4546555886. The cubic root of 421212191 is about 749.6070184196.

The spelling of 421212191 in words is "four hundred twenty-one million, two hundred twelve thousand, one hundred ninety-one".