125629981 has 4 divisors (see below), whose sum is σ = 128000412. Its totient is φ = 123259552.

The previous prime is 125629969. The next prime is 125629993. The reversal of 125629981 is 189926521.

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

It is an interprime number because it is at equal distance from previous prime (125629969) and next prime (125629993).

It can be written as a sum of positive squares in 2 ways, for example, as 74736025 + 50893956 = 8645^2 + 7134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-125629981 is a prime.

It is a super-2 number, since 2×125629981² = 31565784252120722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125629901) 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, 1185136 + ... + 1185241.

It is an arithmetic number, because the mean of its divisors is an integer number (32000103).

Almost surely, 2^125629981 is an apocalyptic number.

It is an amenable number.

125629981 is a deficient number, since it is larger than the sum of its proper divisors (2370431).

125629981 is an equidigital number, since it uses as much as digits as its factorization.

125629981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2370430.

The product of its digits is 77760, while the sum is 43.

The square root of 125629981 is about 11208.4780858063. The cubic root of 125629981 is about 500.8385674896.

The spelling of 125629981 in words is "one hundred twenty-five million, six hundred twenty-nine thousand, nine hundred eighty-one".