1218666855 has 64 divisors (see below), whose sum is σ = 2312893440. Its totient is φ = 536116224.

The previous prime is 1218666853. The next prime is 1218666887. The reversal of 1218666855 is 5586668121.

It is not a de Polignac number, because 1218666855 - 2¹ = 1218666853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218666853) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1421587 + ... + 1422443.

It is an arithmetic number, because the mean of its divisors is an integer number (36138960).

Almost surely, 2^1218666855 is an apocalyptic number.

1218666855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1218666855 is a deficient number, since it is larger than the sum of its proper divisors (1094226585).

1218666855 is a wasteful number, since it uses less digits than its factorization.

1218666855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1368.

The product of its digits is 691200, while the sum is 48.

The square root of 1218666855 is about 34909.4092616876. The cubic root of 1218666855 is about 1068.1403792597.

The spelling of 1218666855 in words is "one billion, two hundred eighteen million, six hundred sixty-six thousand, eight hundred fifty-five".