126278809 has 4 divisors (see below), whose sum is σ = 131769216. Its totient is φ = 120788404.

The previous prime is 126278783. The next prime is 126278819. The reversal of 126278809 is 908872621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 908872621 = 67 ⋅13565263.

It is a cyclic number.

It is not a de Polignac number, because 126278809 - 2¹⁵ = 126246041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126278819) 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, 2745169 + ... + 2745214.

It is an arithmetic number, because the mean of its divisors is an integer number (32942304).

Almost surely, 2^126278809 is an apocalyptic number.

It is an amenable number.

126278809 is a deficient number, since it is larger than the sum of its proper divisors (5490407).

126278809 is an equidigital number, since it uses as much as digits as its factorization.

126278809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5490406.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 126278809 is about 11237.3844376705. The cubic root of 126278809 is about 501.6992969042.

The spelling of 126278809 in words is "one hundred twenty-six million, two hundred seventy-eight thousand, eight hundred nine".