2216861 has 2 divisors, whose sum is σ = 2216862. Its totient is φ = 2216860.

The previous prime is 2216857. The next prime is 2216873. The reversal of 2216861 is 1686122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1705636 + 511225 = 1306^2 + 715^2 .

It is a cyclic number.

It is not a de Polignac number, because 2216861 - 2² = 2216857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2216861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2216821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1108430 + 1108431.

It is an arithmetic number, because the mean of its divisors is an integer number (1108431).

2^2216861 is an apocalyptic number.

It is an amenable number.

2216861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2216861 is an equidigital number, since it uses as much as digits as its factorization.

2216861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 26.

The square root of 2216861 is about 1488.9126905229. The cubic root of 2216861 is about 130.3905611558.

The spelling of 2216861 in words is "two million, two hundred sixteen thousand, eight hundred sixty-one".