1218312138 has 8 divisors (see below), whose sum is σ = 2436624288. Its totient is φ = 406104044.

The previous prime is 1218312107. The next prime is 1218312169. The reversal of 1218312138 is 8312138121.

It is an interprime number because it is at equal distance from previous prime (1218312107) and next prime (1218312169).

It is a sphenic number, since it is the product of 3 distinct primes.

1218312138 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101526006 + ... + 101526017.

It is an arithmetic number, because the mean of its divisors is an integer number (304578036).

Almost surely, 2^1218312138 is an apocalyptic number.

1218312138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1218312138 is a wasteful number, since it uses less digits than its factorization.

1218312138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203052028.

The product of its digits is 2304, while the sum is 30.

The square root of 1218312138 is about 34904.3283562369. The cubic root of 1218312138 is about 1068.0367347687.

The spelling of 1218312138 in words is "one billion, two hundred eighteen million, three hundred twelve thousand, one hundred thirty-eight".