125912781 has 12 divisors (see below), whose sum is σ = 182585052. Its totient is φ = 83613696.

The previous prime is 125912779. The next prime is 125912819. The reversal of 125912781 is 187219521.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 76842756 + 49070025 = 8766^2 + 7005^2 .

It is not a de Polignac number, because 125912781 - 2¹ = 125912779 is a prime.

It is a super-2 number, since 2×125912781² = 31708056838307922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125902781) 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 11 ways as a sum of consecutive naturals, for example, 24906 + ... + 29531.

It is an arithmetic number, because the mean of its divisors is an integer number (15215421).

Almost surely, 2^125912781 is an apocalyptic number.

It is an amenable number.

125912781 is a deficient number, since it is larger than the sum of its proper divisors (56672271).

125912781 is a wasteful number, since it uses less digits than its factorization.

125912781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54700 (or 54697 counting only the distinct ones).

The product of its digits is 10080, while the sum is 36.

The square root of 125912781 is about 11221.0864447254. The cubic root of 125912781 is about 501.2140909137.

The spelling of 125912781 in words is "one hundred twenty-five million, nine hundred twelve thousand, seven hundred eighty-one".