2185409 has 2 divisors, whose sum is σ = 2185410. Its totient is φ = 2185408.

The previous prime is 2185387. The next prime is 2185427. The reversal of 2185409 is 9045812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2002225 + 183184 = 1415^2 + 428^2 .

It is a cyclic number.

It is not a de Polignac number, because 2185409 - 2²⁰ = 1136833 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (2185429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1092704 + 1092705.

It is an arithmetic number, because the mean of its divisors is an integer number (1092705).

2^2185409 is an apocalyptic number.

It is an amenable number.

2185409 is a deficient number, since it is larger than the sum of its proper divisors (1).

2185409 is an equidigital number, since it uses as much as digits as its factorization.

2185409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 2185409 is about 1478.3128897497. The cubic root of 2185409 is about 129.7709774357.

The spelling of 2185409 in words is "two million, one hundred eighty-five thousand, four hundred nine".