1861225 has 6 divisors (see below), whose sum is σ = 2307950. Its totient is φ = 1488960.

The previous prime is 1861219. The next prime is 1861253. The reversal of 1861225 is 5221681.

It can be written as a sum of positive squares in 3 ways, for example, as 729 + 1860496 = 27^2 + 1364^2 .

It is not a de Polignac number, because 1861225 - 2¹¹ = 1859177 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 74449 = 1861225 / (1 + 8 + 6 + 1 + 2 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 1861225.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37200 + ... + 37249.

2^1861225 is an apocalyptic number.

It is an amenable number.

1861225 is a deficient number, since it is larger than the sum of its proper divisors (446725).

1861225 is an equidigital number, since it uses as much as digits as its factorization.

1861225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74459 (or 74454 counting only the distinct ones).

The product of its digits is 960, while the sum is 25.

The square root of 1861225 is about 1364.2672025670. The cubic root of 1861225 is about 123.0078872154.

The spelling of 1861225 in words is "one million, eight hundred sixty-one thousand, two hundred twenty-five".