1218493 has 4 divisors (see below), whose sum is σ = 1260540. Its totient is φ = 1176448.

The previous prime is 1218487. The next prime is 1218533. The reversal of 1218493 is 3948121.

It is a happy number.

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 375769 + 842724 = 613^2 + 918^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1218493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20980 + ... + 21037.

It is an arithmetic number, because the mean of its divisors is an integer number (315135).

2^1218493 is an apocalyptic number.

It is an amenable number.

1218493 is a deficient number, since it is larger than the sum of its proper divisors (42047).

1218493 is an equidigital number, since it uses as much as digits as its factorization.

1218493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42046.

The product of its digits is 1728, while the sum is 28.

The square root of 1218493 is about 1103.8537040750. The cubic root of 1218493 is about 106.8089583213.

Adding to 1218493 its product of digits (1728), we get a palindrome (1220221).

It can be divided in two parts, 1218 and 493, that added together give a triangular number (1711 = T₅₈).

The spelling of 1218493 in words is "one million, two hundred eighteen thousand, four hundred ninety-three".