126509609 has 2 divisors, whose sum is σ = 126509610. Its totient is φ = 126509608.

The previous prime is 126509567. The next prime is 126509611. The reversal of 126509609 is 906905621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71453209 + 55056400 = 8453^2 + 7420^2 .

It is an emirp because it is prime and its reverse (906905621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 126509609 - 2²⁴ = 109732393 is a prime.

Together with 126509611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (126509639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63254804 + 63254805.

It is an arithmetic number, because the mean of its divisors is an integer number (63254805).

Almost surely, 2^126509609 is an apocalyptic number.

It is an amenable number.

126509609 is a deficient number, since it is larger than the sum of its proper divisors (1).

126509609 is an equidigital number, since it uses as much as digits as its factorization.

126509609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 126509609 is about 11247.6490432445. The cubic root of 126509609 is about 502.0047631067.

The spelling of 126509609 in words is "one hundred twenty-six million, five hundred nine thousand, six hundred nine".