1866139 has 4 divisors (see below), whose sum is σ = 2035800. Its totient is φ = 1696480.

The previous prime is 1866131. The next prime is 1866143. The reversal of 1866139 is 9316681.

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

It is a cyclic number.

It is not a de Polignac number, because 1866139 - 2³ = 1866131 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866131) 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 3 ways as a sum of consecutive naturals, for example, 84814 + ... + 84835.

It is an arithmetic number, because the mean of its divisors is an integer number (508950).

2^1866139 is an apocalyptic number.

1866139 is a deficient number, since it is larger than the sum of its proper divisors (169661).

1866139 is a wasteful number, since it uses less digits than its factorization.

1866139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169660.

The product of its digits is 7776, while the sum is 34.

The square root of 1866139 is about 1366.0669822523. The cubic root of 1866139 is about 123.1160470871.

The spelling of 1866139 in words is "one million, eight hundred sixty-six thousand, one hundred thirty-nine".