126872509 has 4 divisors (see below), whose sum is σ = 126909216. Its totient is φ = 126835804.

The previous prime is 126872507. The next prime is 126872521. The reversal of 126872509 is 905278621.

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.

It is a cyclic number.

It is not a de Polignac number, because 126872509 - 2¹ = 126872507 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126872503) 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, 12559 + ... + 20284.

It is an arithmetic number, because the mean of its divisors is an integer number (31727304).

Almost surely, 2^126872509 is an apocalyptic number.

It is an amenable number.

126872509 is a deficient number, since it is larger than the sum of its proper divisors (36707).

126872509 is an equidigital number, since it uses as much as digits as its factorization.

126872509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36706.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 126872509 is about 11263.7697508427. The cubic root of 126872509 is about 502.4843145851.

The spelling of 126872509 in words is "one hundred twenty-six million, eight hundred seventy-two thousand, five hundred nine".