1218188242 has 4 divisors (see below), whose sum is σ = 1827282366. Its totient is φ = 609094120.

The previous prime is 1218188233. The next prime is 1218188267. The reversal of 1218188242 is 2428818121.

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

It can be written as a sum of positive squares in only one way, i.e., 968516641 + 249671601 = 31121^2 + 15801^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304547059 + ... + 304547062.

Almost surely, 2^1218188242 is an apocalyptic number.

1218188242 is a deficient number, since it is larger than the sum of its proper divisors (609094124).

1218188242 is an equidigital number, since it uses as much as digits as its factorization.

1218188242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609094123.

The product of its digits is 16384, while the sum is 37.

The square root of 1218188242 is about 34902.5535168990. The cubic root of 1218188242 is about 1068.0005289500. Note that the first 3 decimals are identical.

The spelling of 1218188242 in words is "one billion, two hundred eighteen million, one hundred eighty-eight thousand, two hundred forty-two".