125866519 has 4 divisors (see below), whose sum is σ = 126980496. Its totient is φ = 124752544.

The previous prime is 125866463. The next prime is 125866549. The reversal of 125866519 is 915668521.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-125866519 is a prime.

It is a super-2 number, since 2×125866519² = 31684761210354722, 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 (125866549) 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, 556819 + ... + 557044.

It is an arithmetic number, because the mean of its divisors is an integer number (31745124).

Almost surely, 2^125866519 is an apocalyptic number.

125866519 is a deficient number, since it is larger than the sum of its proper divisors (1113977).

125866519 is a wasteful number, since it uses less digits than its factorization.

125866519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113976.

The product of its digits is 129600, while the sum is 43.

The square root of 125866519 is about 11219.0248684990. The cubic root of 125866519 is about 501.1526991937.

The spelling of 125866519 in words is "one hundred twenty-five million, eight hundred sixty-six thousand, five hundred nineteen".