1218408811 has 4 divisors (see below), whose sum is σ = 1218500712. Its totient is φ = 1218316912.

The previous prime is 1218408761. The next prime is 1218408817. The reversal of 1218408811 is 1188048121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1218408811 - 2⁹ = 1218408299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1218408817) 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, 21850 + ... + 53983.

It is an arithmetic number, because the mean of its divisors is an integer number (304625178).

Almost surely, 2^1218408811 is an apocalyptic number.

1218408811 is a deficient number, since it is larger than the sum of its proper divisors (91901).

1218408811 is an equidigital number, since it uses as much as digits as its factorization.

1218408811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91900.

The product of its (nonzero) digits is 4096, while the sum is 34.

The square root of 1218408811 is about 34905.7131570177. The cubic root of 1218408811 is about 1068.0649835732.

The spelling of 1218408811 in words is "one billion, two hundred eighteen million, four hundred eight thousand, eight hundred eleven".