126689 has 4 divisors (see below), whose sum is σ = 127680. Its totient is φ = 125700.

The previous prime is 126683. The next prime is 126691. The reversal of 126689 is 986621.

126689 is nontrivially palindromic in base 16.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 986621 = 83 ⋅11887.

It is a cyclic number.

It is not a de Polignac number, because 126689 - 2⁸ = 126433 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (126683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269 + ... + 570.

It is an arithmetic number, because the mean of its divisors is an integer number (31920).

2¹²⁶⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

126689 is a deficient number, since it is larger than the sum of its proper divisors (991).

126689 is an equidigital number, since it uses as much as digits as its factorization.

126689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990.

The product of its digits is 5184, while the sum is 32.

The square root of 126689 is about 355.9339826428. The cubic root of 126689 is about 50.2241932453.

The spelling of 126689 in words is "one hundred twenty-six thousand, six hundred eighty-nine".