125981 has 4 divisors (see below), whose sum is σ = 128412. Its totient is φ = 123552.

The previous prime is 125963. The next prime is 126001. The reversal of 125981 is 189521.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 189521 = 79 ⋅2399.

It can be written as a sum of positive squares in 2 ways, for example, as 70756 + 55225 = 266^2 + 235^2 .

It is a cyclic number.

It is not a de Polignac number, because 125981 - 2¹⁴ = 109597 is a prime.

It is a super-2 number, since 2×125981² = 31742424722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 125981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125921) 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, 1136 + ... + 1241.

It is an arithmetic number, because the mean of its divisors is an integer number (32103).

2¹²⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

125981 is a deficient number, since it is larger than the sum of its proper divisors (2431).

125981 is an equidigital number, since it uses as much as digits as its factorization.

125981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2430.

The product of its digits is 720, while the sum is 26.

The square root of 125981 is about 354.9380227589. The cubic root of 125981 is about 50.1304593113.

The spelling of 125981 in words is "one hundred twenty-five thousand, nine hundred eighty-one".