126875809 has 4 divisors (see below), whose sum is σ = 127239700. Its totient is φ = 126511920.

The previous prime is 126875759. The next prime is 126875813. The reversal of 126875809 is 908578621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908578621 = 24413 ⋅37217.

It can be written as a sum of positive squares in 2 ways, for example, as 96040000 + 30835809 = 9800^2 + 5553^2 .

It is a cyclic number.

It is not a de Polignac number, because 126875809 - 2⁷ = 126875681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126875869) 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, 181422 + ... + 182119.

It is an arithmetic number, because the mean of its divisors is an integer number (31809925).

Almost surely, 2^126875809 is an apocalyptic number.

It is an amenable number.

126875809 is a deficient number, since it is larger than the sum of its proper divisors (363891).

126875809 is an equidigital number, since it uses as much as digits as its factorization.

126875809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363890.

The product of its (nonzero) digits is 241920, while the sum is 46.

The square root of 126875809 is about 11263.9162372596. The cubic root of 126875809 is about 502.4886711471.

It can be divided in two parts, 12687 and 5809, that added together give a square (18496 = 136²).

The spelling of 126875809 in words is "one hundred twenty-six million, eight hundred seventy-five thousand, eight hundred nine".