11812861 has 4 divisors (see below), whose sum is σ = 11848252. Its totient is φ = 11777472.

The previous prime is 11812849. The next prime is 11812873. The reversal of 11812861 is 16821811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16821811 = 3517 ⋅4783.

It is an interprime number because it is at equal distance from previous prime (11812849) and next prime (11812873).

It can be written as a sum of positive squares in 2 ways, for example, as 2540836 + 9272025 = 1594^2 + 3045^2 .

It is a cyclic number.

It is not a de Polignac number, because 11812861 - 2⁷ = 11812733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11812811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17190 + ... + 17863.

It is an arithmetic number, because the mean of its divisors is an integer number (2962063).

Almost surely, 2^11812861 is an apocalyptic number.

It is an amenable number.

11812861 is a deficient number, since it is larger than the sum of its proper divisors (35391).

11812861 is an equidigital number, since it uses as much as digits as its factorization.

11812861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35390.

The product of its digits is 768, while the sum is 28.

The square root of 11812861 is about 3436.9842885879. The cubic root of 11812861 is about 227.7464928853.

The spelling of 11812861 in words is "eleven million, eight hundred twelve thousand, eight hundred sixty-one".