2218861 has 2 divisors, whose sum is σ = 2218862. Its totient is φ = 2218860.

The previous prime is 2218837. The next prime is 2218871. The reversal of 2218861 is 1688122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1943236 + 275625 = 1394^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 2218861 - 2¹⁹ = 1694573 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2218831) 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 as a sum of consecutive naturals, namely, 1109430 + 1109431.

It is an arithmetic number, because the mean of its divisors is an integer number (1109431).

2^2218861 is an apocalyptic number.

It is an amenable number.

2218861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2218861 is an equidigital number, since it uses as much as digits as its factorization.

2218861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 28.

The square root of 2218861 is about 1489.5841701629. The cubic root of 2218861 is about 130.4297611384.

The spelling of 2218861 in words is "two million, two hundred eighteen thousand, eight hundred sixty-one".