1866538 has 4 divisors (see below), whose sum is σ = 2799810. Its totient is φ = 933268.

The previous prime is 1866521. The next prime is 1866547. The reversal of 1866538 is 8356681.

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

It can be written as a sum of positive squares in only one way, i.e., 1545049 + 321489 = 1243^2 + 567^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1866497 and 1866506.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 466633 + ... + 466636.

2^1866538 is an apocalyptic number.

1866538 is a deficient number, since it is larger than the sum of its proper divisors (933272).

1866538 is an equidigital number, since it uses as much as digits as its factorization.

1866538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933271.

The product of its digits is 34560, while the sum is 37.

The square root of 1866538 is about 1366.2130141380. The cubic root of 1866538 is about 123.1248209605.

It can be divided in two parts, 186 and 6538, that added together give a square (6724 = 82²).

The spelling of 1866538 in words is "one million, eight hundred sixty-six thousand, five hundred thirty-eight".