2190409 has 8 divisors (see below), whose sum is σ = 2375240. Its totient is φ = 2019888.

The previous prime is 2190407. The next prime is 2190413. The reversal of 2190409 is 9040912.

It can be written as a sum of positive squares in 4 ways, for example, as 308025 + 1882384 = 555^2 + 1372^2 .

It is not a de Polignac number, because 2190409 - 2¹ = 2190407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2190403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1699 + ... + 2695.

It is an arithmetic number, because the mean of its divisors is an integer number (296905).

2^2190409 is an apocalyptic number.

It is an amenable number.

2190409 is a deficient number, since it is larger than the sum of its proper divisors (184831).

2190409 is an frugal number, since it uses more digits than its factorization.

2190409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036 (or 1010 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 2190409 is about 1480.0030405374. The cubic root of 2190409 is about 129.8698697829.

The spelling of 2190409 in words is "two million, one hundred ninety thousand, four hundred nine".