125691 has 4 divisors (see below), whose sum is σ = 167592. Its totient is φ = 83792.

The previous prime is 125687. The next prime is 125693. The reversal of 125691 is 196521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 125691 - 2² = 125687 is a prime.

It is a D-number.

125691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (125693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20946 + ... + 20951.

It is an arithmetic number, because the mean of its divisors is an integer number (41898).

2¹²⁵⁶⁹¹ is an apocalyptic number.

125691 is a deficient number, since it is larger than the sum of its proper divisors (41901).

125691 is an equidigital number, since it uses as much as digits as its factorization.

125691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41900.

The product of its digits is 540, while the sum is 24.

The square root of 125691 is about 354.5292653647. The cubic root of 125691 is about 50.0919640818.

The spelling of 125691 in words is "one hundred twenty-five thousand, six hundred ninety-one".