125999 has 4 divisors (see below), whose sum is σ = 126936. Its totient is φ = 125064.

The previous prime is 125963. The next prime is 126001. The reversal of 125999 is 999521.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 125999 - 2⁸ = 125743 is a prime.

It is a Duffinian number.

125999 is a modest number, since divided by 999 gives 125 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125929) 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, 224 + ... + 549.

It is an arithmetic number, because the mean of its divisors is an integer number (31734).

2¹²⁵⁹⁹⁹ is an apocalyptic number.

125999 is a deficient number, since it is larger than the sum of its proper divisors (937).

125999 is an equidigital number, since it uses as much as digits as its factorization.

125999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936.

The product of its digits is 7290, while the sum is 35.

The square root of 125999 is about 354.9633783928. The cubic root of 125999 is about 50.1328467224.

The spelling of 125999 in words is "one hundred twenty-five thousand, nine hundred ninety-nine".