421205191 has 16 divisors (see below), whose sum is σ = 464025600. Its totient is φ = 379162080.

The previous prime is 421205131. The next prime is 421205207. The reversal of 421205191 is 191502124.

It is a happy number.

It is not a de Polignac number, because 421205191 - 2⁷ = 421205063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421205101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 693610 + ... + 694216.

It is an arithmetic number, because the mean of its divisors is an integer number (29001600).

Almost surely, 2^421205191 is an apocalyptic number.

421205191 is a deficient number, since it is larger than the sum of its proper divisors (42820409).

421205191 is a wasteful number, since it uses less digits than its factorization.

421205191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 421205191 is about 20523.2841182887. The cubic root of 421205191 is about 749.6028658979.

The spelling of 421205191 in words is "four hundred twenty-one million, two hundred five thousand, one hundred ninety-one".