1800389 has 2 divisors, whose sum is σ = 1800390. Its totient is φ = 1800388.

The previous prime is 1800377. The next prime is 1800397. The reversal of 1800389 is 9830081.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1612900 + 187489 = 1270^2 + 433^2 .

It is an emirp because it is prime and its reverse (9830081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1800389 - 2²⁰ = 751813 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1800889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900194 + 900195.

It is an arithmetic number, because the mean of its divisors is an integer number (900195).

2^1800389 is an apocalyptic number.

It is an amenable number.

1800389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1800389 is an equidigital number, since it uses as much as digits as its factorization.

1800389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1800389 is about 1341.7857504088. The cubic root of 1800389 is about 121.6528021565.

The spelling of 1800389 in words is "one million, eight hundred thousand, three hundred eighty-nine".