125921 has 2 divisors, whose sum is σ = 125922. Its totient is φ = 125920.

The previous prime is 125899. The next prime is 125927. The reversal of 125921 is 129521.

125921 is nontrivially palindromic in base 16.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70225 + 55696 = 265^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 125921 - 2¹⁰ = 124897 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 125893 and 125902.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 125921.

It is not a weakly prime, because it can be changed into another prime (125927) 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 as a sum of consecutive naturals, namely, 62960 + 62961.

It is an arithmetic number, because the mean of its divisors is an integer number (62961).

2¹²⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

125921 is a deficient number, since it is larger than the sum of its proper divisors (1).

125921 is an equidigital number, since it uses as much as digits as its factorization.

125921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180, while the sum is 20.

The square root of 125921 is about 354.8534908945. The cubic root of 125921 is about 50.1224996317.

Subtracting 125921 from its reverse (129521), we obtain a square (3600 = 60²).

The spelling of 125921 in words is "one hundred twenty-five thousand, nine hundred twenty-one".