1866149 has 4 divisors (see below), whose sum is σ = 1873164. Its totient is φ = 1859136.

The previous prime is 1866143. The next prime is 1866191. The reversal of 1866149 is 9416681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9416681 = 1087 ⋅8663.

It can be written as a sum of positive squares in 2 ways, for example, as 616225 + 1249924 = 785^2 + 1118^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866149 - 2⁸ = 1865893 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3092 + ... + 3645.

It is an arithmetic number, because the mean of its divisors is an integer number (468291).

2^1866149 is an apocalyptic number.

It is an amenable number.

1866149 is a deficient number, since it is larger than the sum of its proper divisors (7015).

1866149 is an equidigital number, since it uses as much as digits as its factorization.

1866149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7014.

The product of its digits is 10368, while the sum is 35.

The square root of 1866149 is about 1366.0706423901. The cubic root of 1866149 is about 123.1162669989.

The spelling of 1866149 in words is "one million, eight hundred sixty-six thousand, one hundred forty-nine".