126689309 has 4 divisors (see below), whose sum is σ = 129635616. Its totient is φ = 123743004.

The previous prime is 126689261. The next prime is 126689327. The reversal of 126689309 is 903986621.

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: 903986621 = 3329 ⋅271549.

It is a cyclic number.

It is not a de Polignac number, because 126689309 - 2²⁰ = 125640733 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 126689309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126689399) 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, 1473089 + ... + 1473174.

It is an arithmetic number, because the mean of its divisors is an integer number (32408904).

Almost surely, 2^126689309 is an apocalyptic number.

It is an amenable number.

126689309 is a deficient number, since it is larger than the sum of its proper divisors (2946307).

126689309 is an equidigital number, since it uses as much as digits as its factorization.

126689309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946306.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 126689309 is about 11255.6345445292. The cubic root of 126689309 is about 502.2423407827.

The spelling of 126689309 in words is "one hundred twenty-six million, six hundred eighty-nine thousand, three hundred nine".