12699209 has 2 divisors, whose sum is σ = 12699210. Its totient is φ = 12699208.

The previous prime is 12699157. The next prime is 12699223. The reversal of 12699209 is 90299621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11971600 + 727609 = 3460^2 + 853^2 .

It is a cyclic number.

It is not a de Polignac number, because 12699209 - 2¹² = 12695113 is a prime.

It is a super-2 number, since 2×12699209² = 322539818451362, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12699229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6349604 + 6349605.

It is an arithmetic number, because the mean of its divisors is an integer number (6349605).

Almost surely, 2^12699209 is an apocalyptic number.

It is an amenable number.

12699209 is a deficient number, since it is larger than the sum of its proper divisors (1).

12699209 is an equidigital number, since it uses as much as digits as its factorization.

12699209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 12699209 is about 3563.5949545368. The cubic root of 12699209 is about 233.3058114931.

The spelling of 12699209 in words is "twelve million, six hundred ninety-nine thousand, two hundred nine".