491420191 has 4 divisors (see below), whose sum is σ = 491495400. Its totient is φ = 491344984.

The previous prime is 491420177. The next prime is 491420197. The reversal of 491420191 is 191024194.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 491420191 - 2¹¹ = 491418143 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 (491420197) 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 in 3 ways as a sum of consecutive naturals, for example, 26761 + ... + 41218.

It is an arithmetic number, because the mean of its divisors is an integer number (122873850).

Almost surely, 2^491420191 is an apocalyptic number.

491420191 is a deficient number, since it is larger than the sum of its proper divisors (75209).

491420191 is an equidigital number, since it uses as much as digits as its factorization.

491420191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75208.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 491420191 is about 22167.9992556839. Note that the first 3 decimals coincide. The cubic root of 491420191 is about 789.1344421659.

The spelling of 491420191 in words is "four hundred ninety-one million, four hundred twenty thousand, one hundred ninety-one".