2194021 has 2 divisors, whose sum is σ = 2194022. Its totient is φ = 2194020.

The previous prime is 2194019. The next prime is 2194051. The reversal of 2194021 is 1204912.

2194021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1653796 + 540225 = 1286^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 2194021 - 2¹ = 2194019 is a prime.

Together with 2194019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2194021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2194051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1097010 + 1097011.

It is an arithmetic number, because the mean of its divisors is an integer number (1097011).

2^2194021 is an apocalyptic number.

It is an amenable number.

2194021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2194021 is an equidigital number, since it uses as much as digits as its factorization.

2194021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 2194021 is about 1481.2228056575. Note that the first 3 decimals coincide. The cubic root of 2194021 is about 129.9412160264.

Adding to 2194021 its reverse (1204912), we get a palindrome (3398933).

The spelling of 2194021 in words is "two million, one hundred ninety-four thousand, twenty-one".