1865389 has 2 divisors, whose sum is σ = 1865390. Its totient is φ = 1865388.

The previous prime is 1865371. The next prime is 1865399. The reversal of 1865389 is 9835681.

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., 1605289 + 260100 = 1267^2 + 510^2 .

It is an emirp because it is prime and its reverse (9835681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1865389 - 2⁷ = 1865261 is a prime.

It is a super-2 number, since 2×1865389² = 6959352242642, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1865329) 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 as a sum of consecutive naturals, namely, 932694 + 932695.

It is an arithmetic number, because the mean of its divisors is an integer number (932695).

2^1865389 is an apocalyptic number.

It is an amenable number.

1865389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1865389 is an equidigital number, since it uses as much as digits as its factorization.

1865389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 40.

The square root of 1865389 is about 1365.7924439680. The cubic root of 1865389 is about 123.0995514584.

The spelling of 1865389 in words is "one million, eight hundred sixty-five thousand, three hundred eighty-nine".