1866145 has 4 divisors (see below), whose sum is σ = 2239380. Its totient is φ = 1492912.

The previous prime is 1866143. The next prime is 1866191. The reversal of 1866145 is 5416681.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1147041 + 719104 = 1071^2 + 848^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866145 - 2¹ = 1866143 is a prime.

It is a super-2 number, since 2×1866145² = 6964994322050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1866143) 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 in 3 ways as a sum of consecutive naturals, for example, 186610 + ... + 186619.

It is an arithmetic number, because the mean of its divisors is an integer number (559845).

2^1866145 is an apocalyptic number.

It is an amenable number.

1866145 is a deficient number, since it is larger than the sum of its proper divisors (373235).

1866145 is an equidigital number, since it uses as much as digits as its factorization.

1866145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373234.

The product of its digits is 5760, while the sum is 31.

The square root of 1866145 is about 1366.0691783361. The cubic root of 1866145 is about 123.1161790343.

The spelling of 1866145 in words is "one million, eight hundred sixty-six thousand, one hundred forty-five".