1818409 has 2 divisors, whose sum is σ = 1818410. Its totient is φ = 1818408.

The previous prime is 1818407. The next prime is 1818413. The reversal of 1818409 is 9048181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 921600 + 896809 = 960^2 + 947^2 .

It is a cyclic number.

It is not a de Polignac number, because 1818409 - 2¹ = 1818407 is a prime.

It is a super-2 number, since 2×1818409² = 6613222582562, which contains 22 as substring.

Together with 1818407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1818407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909204 + 909205.

It is an arithmetic number, because the mean of its divisors is an integer number (909205).

2^1818409 is an apocalyptic number.

It is an amenable number.

1818409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818409 is an equidigital number, since it uses as much as digits as its factorization.

1818409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 1818409 is about 1348.4839635680. The cubic root of 1818409 is about 122.0573277113.

The spelling of 1818409 in words is "one million, eight hundred eighteen thousand, four hundred nine".