491111911 has 2 divisors, whose sum is σ = 491111912. Its totient is φ = 491111910.

The previous prime is 491111869. The next prime is 491111923. The reversal of 491111911 is 119111194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491111911 - 2⁷ = 491111783 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491111911.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491111941) 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, 245555955 + 245555956.

It is an arithmetic number, because the mean of its divisors is an integer number (245555956).

Almost surely, 2^491111911 is an apocalyptic number.

491111911 is a deficient number, since it is larger than the sum of its proper divisors (1).

491111911 is an equidigital number, since it uses as much as digits as its factorization.

491111911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324, while the sum is 28.

The square root of 491111911 is about 22161.0448986504. The cubic root of 491111911 is about 788.9693931518.

The spelling of 491111911 in words is "four hundred ninety-one million, one hundred eleven thousand, nine hundred eleven".