12905209 has 2 divisors, whose sum is σ = 12905210. Its totient is φ = 12905208.

The previous prime is 12905183. The next prime is 12905219. The reversal of 12905209 is 90250921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7683984 + 5221225 = 2772^2 + 2285^2 .

It is an emirp because it is prime and its reverse (90250921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12905209 - 2¹⁵ = 12872441 is a prime.

It is a super-4 number, since 4×12905209⁴ (a number of 30 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (12905219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6452604 + 6452605.

It is an arithmetic number, because the mean of its divisors is an integer number (6452605).

Almost surely, 2^12905209 is an apocalyptic number.

It is an amenable number.

12905209 is a deficient number, since it is larger than the sum of its proper divisors (1).

12905209 is an equidigital number, since it uses as much as digits as its factorization.

12905209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 12905209 is about 3592.3820787884. The cubic root of 12905209 is about 234.5605731232.

The spelling of 12905209 in words is "twelve million, nine hundred five thousand, two hundred nine".