126505609 has 4 divisors (see below), whose sum is σ = 126528516. Its totient is φ = 126482704.

The previous prime is 126505607. The next prime is 126505651. The reversal of 126505609 is 906505621.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2673225 + 123832384 = 1635^2 + 11128^2 .

It is a cyclic number.

It is not a de Polignac number, because 126505609 - 2¹ = 126505607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126505601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2487 + ... + 16099.

It is an arithmetic number, because the mean of its divisors is an integer number (31632129).

Almost surely, 2^126505609 is an apocalyptic number.

It is an amenable number.

126505609 is a deficient number, since it is larger than the sum of its proper divisors (22907).

126505609 is an equidigital number, since it uses as much as digits as its factorization.

126505609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22906.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 126505609 is about 11247.4712269025. The cubic root of 126505609 is about 501.9994722300. Note that the first 3 decimals are identical.

The spelling of 126505609 in words is "one hundred twenty-six million, five hundred five thousand, six hundred nine".