125661 has 4 divisors (see below), whose sum is σ = 167552. Its totient is φ = 83772.

The previous prime is 125659. The next prime is 125669. The reversal of 125661 is 166521.

It is a happy number.

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 125661 - 2¹ = 125659 is a prime.

It is a D-number.

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 (125669) 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, 20941 + ... + 20946.

It is an arithmetic number, because the mean of its divisors is an integer number (41888).

2¹²⁵⁶⁶¹ is an apocalyptic number.

It is an amenable number.

125661 is a deficient number, since it is larger than the sum of its proper divisors (41891).

125661 is an equidigital number, since it uses as much as digits as its factorization.

125661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41890.

The product of its digits is 360, while the sum is 21.

The square root of 125661 is about 354.4869532155. The cubic root of 125661 is about 50.0879784384.

The spelling of 125661 in words is "one hundred twenty-five thousand, six hundred sixty-one".