1205609 has 2 divisors, whose sum is σ = 1205610. Its totient is φ = 1205608.

The previous prime is 1205563. The next prime is 1205627. The reversal of 1205609 is 9065021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 994009 + 211600 = 997^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205609 - 2¹² = 1201513 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1205629) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602804 + 602805.

It is an arithmetic number, because the mean of its divisors is an integer number (602805).

2^1205609 is an apocalyptic number.

It is an amenable number.

1205609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205609 is an equidigital number, since it uses as much as digits as its factorization.

1205609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1205609 is about 1098.0022768647. The cubic root of 1205609 is about 106.4311677305.

The spelling of 1205609 in words is "one million, two hundred five thousand, six hundred nine".