1861239 has 4 divisors (see below), whose sum is σ = 2481656. Its totient is φ = 1240824.

The previous prime is 1861219. The next prime is 1861253. The reversal of 1861239 is 9321681.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1861239 - 2⁸ = 1860983 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861219) 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, 310204 + ... + 310209.

It is an arithmetic number, because the mean of its divisors is an integer number (620414).

2^1861239 is an apocalyptic number.

1861239 is a deficient number, since it is larger than the sum of its proper divisors (620417).

1861239 is an equidigital number, since it uses as much as digits as its factorization.

1861239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620416.

The product of its digits is 2592, while the sum is 30.

The square root of 1861239 is about 1364.2723335170. The cubic root of 1861239 is about 123.0081956334.

The spelling of 1861239 in words is "one million, eight hundred sixty-one thousand, two hundred thirty-nine".