103217209 has 2 divisors, whose sum is σ = 103217210. Its totient is φ = 103217208.

The previous prime is 103217207. The next prime is 103217237. The reversal of 103217209 is 902712301.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91623184 + 11594025 = 9572^2 + 3405^2 .

It is an emirp because it is prime and its reverse (902712301) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 103217209 - 2¹ = 103217207 is a prime.

Together with 103217207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (103217207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51608604 + 51608605.

It is an arithmetic number, because the mean of its divisors is an integer number (51608605).

Almost surely, 2^103217209 is an apocalyptic number.

It is an amenable number.

103217209 is a deficient number, since it is larger than the sum of its proper divisors (1).

103217209 is an equidigital number, since it uses as much as digits as its factorization.

103217209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 103217209 is about 10159.5870486944. The cubic root of 103217209 is about 469.0840907406.

The spelling of 103217209 in words is "one hundred three million, two hundred seventeen thousand, two hundred nine".