1866312243 has 12 divisors (see below), whose sum is σ = 2696162040. Its totient is φ = 1244033856.

The previous prime is 1866312191. The next prime is 1866312247. The reversal of 1866312243 is 3422136681.

1866312243 is a `hidden beast` number, since 18 + 6 + 631 + 2 + 2 + 4 + 3 = 666.

It is not a de Polignac number, because 1866312243 - 2⁸ = 1866311987 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1866312198 and 1866312207.

It is not an unprimeable number, because it can be changed into a prime (1866312247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 105355 + ... + 121787.

It is an arithmetic number, because the mean of its divisors is an integer number (224680170).

Almost surely, 2^1866312243 is an apocalyptic number.

1866312243 is a deficient number, since it is larger than the sum of its proper divisors (829849797).

1866312243 is a wasteful number, since it uses less digits than its factorization.

1866312243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29058 (or 29055 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 1866312243 is about 43200.8361377416. The cubic root of 1866312243 is about 1231.1985679496.

The spelling of 1866312243 in words is "one billion, eight hundred sixty-six million, three hundred twelve thousand, two hundred forty-three".