126891309 has 4 divisors (see below), whose sum is σ = 169188416. Its totient is φ = 84594204.

The previous prime is 126891263. The next prime is 126891319. The reversal of 126891309 is 903198621.

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 not a de Polignac number, because 126891309 - 2⁸ = 126891053 is a prime.

It is a super-2 number, since 2×126891309² = 32202808599466962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126891319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21148549 + ... + 21148554.

It is an arithmetic number, because the mean of its divisors is an integer number (42297104).

Almost surely, 2^126891309 is an apocalyptic number.

It is an amenable number.

126891309 is a deficient number, since it is larger than the sum of its proper divisors (42297107).

126891309 is an equidigital number, since it uses as much as digits as its factorization.

126891309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42297106.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 126891309 is about 11264.6042540340. The cubic root of 126891309 is about 502.5091327763.

The spelling of 126891309 in words is "one hundred twenty-six million, eight hundred ninety-one thousand, three hundred nine".