1218378685 has 16 divisors (see below), whose sum is σ = 1495872000. Its totient is φ = 952413696.

The previous prime is 1218378643. The next prime is 1218378703. The reversal of 1218378685 is 5868738121.

It is a cyclic number.

It is not a de Polignac number, because 1218378685 - 2¹¹ = 1218376637 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22416 + ... + 54214.

It is an arithmetic number, because the mean of its divisors is an integer number (93492000).

Almost surely, 2^1218378685 is an apocalyptic number.

It is an amenable number.

1218378685 is a deficient number, since it is larger than the sum of its proper divisors (277493315).

1218378685 is an equidigital number, since it uses as much as digits as its factorization.

1218378685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31980.

The product of its digits is 645120, while the sum is 49.

The square root of 1218378685 is about 34905.2816204081. The cubic root of 1218378685 is about 1068.0561806190.

The spelling of 1218378685 in words is "one billion, two hundred eighteen million, three hundred seventy-eight thousand, six hundred eighty-five".