12315209 has 2 divisors, whose sum is σ = 12315210. Its totient is φ = 12315208.

The previous prime is 12315187. The next prime is 12315223. The reversal of 12315209 is 90251321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7139584 + 5175625 = 2672^2 + 2275^2 .

It is an emirp because it is prime and its reverse (90251321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12315209 - 2¹² = 12311113 is a prime.

It is a super-3 number, since 3×12315209³ (a number of 22 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (12315299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6157604 + 6157605.

It is an arithmetic number, because the mean of its divisors is an integer number (6157605).

Almost surely, 2^12315209 is an apocalyptic number.

It is an amenable number.

12315209 is a deficient number, since it is larger than the sum of its proper divisors (1).

12315209 is an equidigital number, since it uses as much as digits as its factorization.

12315209 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 12315209 is about 3509.3032071909. The cubic root of 12315209 is about 230.9301276026.

The spelling of 12315209 in words is "twelve million, three hundred fifteen thousand, two hundred nine".