1866243 has 32 divisors (see below), whose sum is σ = 2889216. Its totient is φ = 1064448.

The previous prime is 1866239. The next prime is 1866247. The reversal of 1866243 is 3426681.

It is an interprime number because it is at equal distance from previous prime (1866239) and next prime (1866247).

It is not a de Polignac number, because 1866243 - 2² = 1866239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1866243.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866247) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43380 + ... + 43422.

It is an arithmetic number, because the mean of its divisors is an integer number (90288).

2^1866243 is an apocalyptic number.

1866243 is a deficient number, since it is larger than the sum of its proper divisors (1022973).

1866243 is a wasteful number, since it uses less digits than its factorization.

1866243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123.

The product of its digits is 6912, while the sum is 30.

The square root of 1866243 is about 1366.1050472054. The cubic root of 1866243 is about 123.1183341320.

The spelling of 1866243 in words is "one million, eight hundred sixty-six thousand, two hundred forty-three".