126661 has 4 divisors (see below), whose sum is σ = 132192. Its totient is φ = 121132.

The previous prime is 126653. The next prime is 126683. The reversal of 126661 is 166621.

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 126661 - 2³ = 126653 is a prime.

It is a Smith number, since the sum of its digits (22) 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 (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, 2731 + ... + 2776.

It is an arithmetic number, because the mean of its divisors is an integer number (33048).

2¹²⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

126661 is a deficient number, since it is larger than the sum of its proper divisors (5531).

126661 is an equidigital number, since it uses as much as digits as its factorization.

126661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5530.

The product of its digits is 432, while the sum is 22.

The square root of 126661 is about 355.8946473326. The cubic root of 126661 is about 50.2204928950.

It can be divided in two parts, 126 and 661, that added together give a palindrome (787).

The spelling of 126661 in words is "one hundred twenty-six thousand, six hundred sixty-one".