1218418161 has 4 divisors (see below), whose sum is σ = 1624557552. Its totient is φ = 812278772.

The previous prime is 1218418153. The next prime is 1218418163. The reversal of 1218418161 is 1618148121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1218418161 - 2³ = 1218418153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1218418163) 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, 203069691 + ... + 203069696.

It is an arithmetic number, because the mean of its divisors is an integer number (406139388).

Almost surely, 2^1218418161 is an apocalyptic number.

It is an amenable number.

1218418161 is a deficient number, since it is larger than the sum of its proper divisors (406139391).

1218418161 is an equidigital number, since it uses as much as digits as its factorization.

1218418161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406139390.

The product of its digits is 3072, while the sum is 33.

The square root of 1218418161 is about 34905.8470889907. The cubic root of 1218418161 is about 1068.0677156562.

The spelling of 1218418161 in words is "one billion, two hundred eighteen million, four hundred eighteen thousand, one hundred sixty-one".