1818191911 has 2 divisors, whose sum is σ = 1818191912. Its totient is φ = 1818191910.

The previous prime is 1818191897. The next prime is 1818191933. The reversal of 1818191911 is 1191918181.

It is a weak prime.

It is an emirp because it is prime and its reverse (1191918181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1818191911 - 2²¹ = 1816094759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1818191971) 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, 909095955 + 909095956.

It is an arithmetic number, because the mean of its divisors is an integer number (909095956).

Almost surely, 2^1818191911 is an apocalyptic number.

1818191911 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818191911 is an equidigital number, since it uses as much as digits as its factorization.

1818191911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 40.

The square root of 1818191911 is about 42640.2616197415. The cubic root of 1818191911 is about 1220.5247028598.

The spelling of 1818191911 in words is "one billion, eight hundred eighteen million, one hundred ninety-one thousand, nine hundred eleven".