2161409 has 2 divisors, whose sum is σ = 2161410. Its totient is φ = 2161408.

The previous prime is 2161373. The next prime is 2161417. The reversal of 2161409 is 9041612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2093809 + 67600 = 1447^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161409 - 2¹² = 2157313 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2161469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080704 + 1080705.

It is an arithmetic number, because the mean of its divisors is an integer number (1080705).

2^2161409 is an apocalyptic number.

It is an amenable number.

2161409 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161409 is an equidigital number, since it uses as much as digits as its factorization.

2161409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 2161409 is about 1470.1731190578. The cubic root of 2161409 is about 129.2941826858.

The spelling of 2161409 in words is "two million, one hundred sixty-one thousand, four hundred nine".