1218858 has 16 divisors (see below), whose sum is σ = 2516736. Its totient is φ = 393120.

The previous prime is 1218853. The next prime is 1218859. The reversal of 1218858 is 8588121.

It is a super-2 number, since 2×1218858² = 2971229648328, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1218853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3091 + ... + 3462.

It is an arithmetic number, because the mean of its divisors is an integer number (157296).

2^1218858 is an apocalyptic number.

1218858 is an abundant number, since it is smaller than the sum of its proper divisors (1297878).

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

1218858 is a wasteful number, since it uses less digits than its factorization.

1218858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6589.

The product of its digits is 5120, while the sum is 33.

The square root of 1218858 is about 1104.0190215753. The cubic root of 1218858 is about 106.8196221434.

It can be divided in two parts, 12188 and 58, that added together give a triangular number (12246 = T₁₅₆).

The spelling of 1218858 in words is "one million, two hundred eighteen thousand, eight hundred fifty-eight".