1241556209 has 2 divisors, whose sum is σ = 1241556210. Its totient is φ = 1241556208.

The previous prime is 1241556193. The next prime is 1241556221. The reversal of 1241556209 is 9026551421.

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., 1019397184 + 222159025 = 31928^2 + 14905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1241556209 - 2⁴ = 1241556193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1241556259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620778104 + 620778105.

It is an arithmetic number, because the mean of its divisors is an integer number (620778105).

Almost surely, 2^1241556209 is an apocalyptic number.

It is an amenable number.

1241556209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1241556209 is an equidigital number, since it uses as much as digits as its factorization.

1241556209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 1241556209 is about 35235.7234777434. The cubic root of 1241556209 is about 1074.7863167130.

The spelling of 1241556209 in words is "one billion, two hundred forty-one million, five hundred fifty-six thousand, two hundred nine".