1818638 has 4 divisors (see below), whose sum is σ = 2727960. Its totient is φ = 909318.

The previous prime is 1818631. The next prime is 1818647. The reversal of 1818638 is 8368181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8368181 = 1277 ⋅6553.

It is a junction number, because it is equal to n+sod(n) for n = 1818598 and 1818607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454658 + ... + 454661.

It is an arithmetic number, because the mean of its divisors is an integer number (681990).

2^1818638 is an apocalyptic number.

1818638 is a deficient number, since it is larger than the sum of its proper divisors (909322).

1818638 is an equidigital number, since it uses as much as digits as its factorization.

1818638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909321.

The product of its digits is 9216, while the sum is 35.

The square root of 1818638 is about 1348.5688710630. The cubic root of 1818638 is about 122.0624512295.

The spelling of 1818638 in words is "one million, eight hundred eighteen thousand, six hundred thirty-eight".