1866361 has 12 divisors (see below), whose sum is σ = 2226420. Its totient is φ = 1559040.

The previous prime is 1866349. The next prime is 1866367. The reversal of 1866361 is 1636681.

1866361 = T₂₈₁ + T₂₈₂ + ... + T₃₂₁.

It can be written as a sum of positive squares in 2 ways, for example, as 60025 + 1806336 = 245^2 + 1344^2 .

It is not a de Polignac number, because 1866361 - 2⁷ = 1866233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1866367) 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 11 ways as a sum of consecutive naturals, for example, 1545 + ... + 2473.

It is an arithmetic number, because the mean of its divisors is an integer number (185535).

2^1866361 is an apocalyptic number.

It is an amenable number.

1866361 is a deficient number, since it is larger than the sum of its proper divisors (360059).

1866361 is an equidigital number, since it uses as much as digits as its factorization.

1866361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984 (or 977 counting only the distinct ones).

The product of its digits is 5184, while the sum is 31.

The square root of 1866361 is about 1366.1482350023. The cubic root of 1866361 is about 123.1209289454.

The spelling of 1866361 in words is "one million, eight hundred sixty-six thousand, three hundred sixty-one".