2190209 has 4 divisors (see below), whose sum is σ = 2503104. Its totient is φ = 1877316.

The previous prime is 2190203. The next prime is 2190217. The reversal of 2190209 is 9020912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2190209 - 2⁴ = 2190193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2190203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156437 + ... + 156450.

It is an arithmetic number, because the mean of its divisors is an integer number (625776).

2^2190209 is an apocalyptic number.

It is an amenable number.

2190209 is a deficient number, since it is larger than the sum of its proper divisors (312895).

2190209 is an equidigital number, since it uses as much as digits as its factorization.

2190209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312894.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 2190209 is about 1479.9354715662. The cubic root of 2190209 is about 129.8659169801.

The spelling of 2190209 in words is "two million, one hundred ninety thousand, two hundred nine".