209709413 has 2 divisors, whose sum is σ = 209709414. Its totient is φ = 209709412.

The previous prime is 209709391. The next prime is 209709421. The reversal of 209709413 is 314907902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206726884 + 2982529 = 14378^2 + 1727^2 .

It is a cyclic number.

It is not a de Polignac number, because 209709413 - 2⁶ = 209709349 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209709463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104854706 + 104854707.

It is an arithmetic number, because the mean of its divisors is an integer number (104854707).

Almost surely, 2^209709413 is an apocalyptic number.

It is an amenable number.

209709413 is a deficient number, since it is larger than the sum of its proper divisors (1).

209709413 is an equidigital number, since it uses as much as digits as its factorization.

209709413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 209709413 is about 14481.3470713190. The cubic root of 209709413 is about 594.1179057932.

The spelling of 209709413 in words is "two hundred nine million, seven hundred nine thousand, four hundred thirteen".