1218389508 has 144 divisors (see below), whose sum is σ = 3640000000. Its totient is φ = 343429632.

The previous prime is 1218389503. The next prime is 1218389509. The reversal of 1218389508 is 8059838121.

It is a happy number.

1218389508 is a `hidden beast` number, since 1 + 218 + 389 + 50 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218389503) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 974868 + ... + 976116.

Almost surely, 2^1218389508 is an apocalyptic number.

1218389508 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1218389508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1820000000).

1218389508 is an abundant number, since it is smaller than the sum of its proper divisors (2421610492).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1218389508 is a wasteful number, since it uses less digits than its factorization.

1218389508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 1218389508 is about 34905.4366539082. The cubic root of 1218389508 is about 1068.0593431655.

The spelling of 1218389508 in words is "one billion, two hundred eighteen million, three hundred eighty-nine thousand, five hundred eight".