2209891 has 2 divisors, whose sum is σ = 2209892. Its totient is φ = 2209890.

The previous prime is 2209853. The next prime is 2209901. The reversal of 2209891 is 1989022.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2209891 - 2⁷ = 2209763 is a prime.

It is not a weakly prime, because it can be changed into another prime (2209811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1104945 + 1104946.

It is an arithmetic number, because the mean of its divisors is an integer number (1104946).

2^2209891 is an apocalyptic number.

2209891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2209891 is an equidigital number, since it uses as much as digits as its factorization.

2209891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 2209891 is about 1486.5702136125. The cubic root of 2209891 is about 130.2537646749.

The spelling of 2209891 in words is "two million, two hundred nine thousand, eight hundred ninety-one".