126605 has 4 divisors (see below), whose sum is σ = 151932. Its totient is φ = 101280.

The previous prime is 126601. The next prime is 126611. The reversal of 126605 is 506621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 506621 = 23 ⋅22027.

It can be written as a sum of positive squares in 2 ways, for example, as 75076 + 51529 = 274^2 + 227^2 .

It is not a de Polignac number, because 126605 - 2² = 126601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126601) 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, 12656 + ... + 12665.

It is an arithmetic number, because the mean of its divisors is an integer number (37983).

2¹²⁶⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

126605 is a deficient number, since it is larger than the sum of its proper divisors (25327).

126605 is an equidigital number, since it uses as much as digits as its factorization.

126605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25326.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 126605 is about 355.8159636666. The cubic root of 126605 is about 50.2130905582.

The spelling of 126605 in words is "one hundred twenty-six thousand, six hundred five".