2605409 has 2 divisors, whose sum is σ = 2605410. Its totient is φ = 2605408.

The previous prime is 2605391. The next prime is 2605411. The reversal of 2605409 is 9045062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2411809 + 193600 = 1553^2 + 440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2605409 is a prime.

Together with 2605411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2605439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1302704 + 1302705.

It is an arithmetic number, because the mean of its divisors is an integer number (1302705).

2^2605409 is an apocalyptic number.

It is an amenable number.

2605409 is a deficient number, since it is larger than the sum of its proper divisors (1).

2605409 is an equidigital number, since it uses as much as digits as its factorization.

2605409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 2605409 is about 1614.1279379281. The cubic root of 2605409 is about 137.6021763954.

The spelling of 2605409 in words is "two million, six hundred five thousand, four hundred nine".