1218365 has 4 divisors (see below), whose sum is σ = 1462044. Its totient is φ = 974688.

The previous prime is 1218313. The next prime is 1218367. The reversal of 1218365 is 5638121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 606841 + 611524 = 779^2 + 782^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218365 - 2²⁰ = 169789 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121832 + ... + 121841.

It is an arithmetic number, because the mean of its divisors is an integer number (365511).

2^1218365 is an apocalyptic number.

It is an amenable number.

1218365 is a deficient number, since it is larger than the sum of its proper divisors (243679).

1218365 is an equidigital number, since it uses as much as digits as its factorization.

1218365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243678.

The product of its digits is 1440, while the sum is 26.

The square root of 1218365 is about 1103.7957238547. The cubic root of 1218365 is about 106.8052181752.

The spelling of 1218365 in words is "one million, two hundred eighteen thousand, three hundred sixty-five".