1218818340 has 120 divisors (see below), whose sum is σ = 3841077240. Its totient is φ = 323523072.

The previous prime is 1218818317. The next prime is 1218818407. The reversal of 1218818340 is 438188121.

It can be written as a sum of positive squares in 4 ways, for example, as 4435236 + 1214383104 = 2106^2 + 34848^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1218818295 and 1218818304.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 375846 + ... + 379074.

It is an arithmetic number, because the mean of its divisors is an integer number (32008977).

Almost surely, 2^1218818340 is an apocalyptic number.

1218818340 is a gapful number since it is divisible by the number (10) 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 1218818340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1920538620).

1218818340 is an abundant number, since it is smaller than the sum of its proper divisors (2622258900).

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

1218818340 is a wasteful number, since it uses less digits than its factorization.

1218818340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3483 (or 3472 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 1218818340 is about 34911.5788815115. The cubic root of 1218818340 is about 1068.1846354184.

The spelling of 1218818340 in words is "one billion, two hundred eighteen million, eight hundred eighteen thousand, three hundred forty".