1861219 has 2 divisors, whose sum is σ = 1861220. Its totient is φ = 1861218.

The previous prime is 1861187. The next prime is 1861253. The reversal of 1861219 is 9121681.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (9121681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861219 - 2⁵ = 1861187 is a prime.

It is a super-2 number, since 2×1861219² = 6928272331922, which contains 22 as substring.

It is a zygodrome in base 2.

It is not a weakly prime, because it can be changed into another prime (1861019) by changing a digit.

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 as a sum of consecutive naturals, namely, 930609 + 930610.

It is an arithmetic number, because the mean of its divisors is an integer number (930610).

2^1861219 is an apocalyptic number.

1861219 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861219 is an equidigital number, since it uses as much as digits as its factorization.

1861219 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 28.

The square root of 1861219 is about 1364.2650035825. The cubic root of 1861219 is about 123.0077550358.

It can be divided in two parts, 1861 and 219, that added together give a triangular number (2080 = T₆₄).

The spelling of 1861219 in words is "one million, eight hundred sixty-one thousand, two hundred nineteen".