209536121 has 2 divisors, whose sum is σ = 209536122. Its totient is φ = 209536120.

The previous prime is 209536109. The next prime is 209536127. The reversal of 209536121 is 121635902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133148521 + 76387600 = 11539^2 + 8740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209536121 is a prime.

It is not a weakly prime, because it can be changed into another prime (209536127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104768060 + 104768061.

It is an arithmetic number, because the mean of its divisors is an integer number (104768061).

Almost surely, 2^209536121 is an apocalyptic number.

It is an amenable number.

209536121 is a deficient number, since it is larger than the sum of its proper divisors (1).

209536121 is an equidigital number, since it uses as much as digits as its factorization.

209536121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 209536121 is about 14475.3625515909. The cubic root of 209536121 is about 593.9542122158.

The spelling of 209536121 in words is "two hundred nine million, five hundred thirty-six thousand, one hundred twenty-one".