1218389855 has 8 divisors (see below), whose sum is σ = 1462255200. Its totient is φ = 974586976.

The previous prime is 1218389819. The next prime is 1218389923. The reversal of 1218389855 is 5589838121.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1218389855 - 2¹⁸ = 1218127711 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68366 + ... + 84324.

It is an arithmetic number, because the mean of its divisors is an integer number (182781900).

Almost surely, 2^1218389855 is an apocalyptic number.

1218389855 is a deficient number, since it is larger than the sum of its proper divisors (243865345).

1218389855 is a wasteful number, since it uses less digits than its factorization.

1218389855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31233.

The product of its digits is 691200, while the sum is 50.

The square root of 1218389855 is about 34905.4416244803. The cubic root of 1218389855 is about 1068.0594445607.

The spelling of 1218389855 in words is "one billion, two hundred eighteen million, three hundred eighty-nine thousand, eight hundred fifty-five".