125911987 has 4 divisors (see below), whose sum is σ = 129973696. Its totient is φ = 121850280.

The previous prime is 125911969. The next prime is 125912009. The reversal of 125911987 is 789119521.

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

It is a cyclic number.

It is not a de Polignac number, because 125911987 - 2¹⁵ = 125879219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125911937) 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 3 ways as a sum of consecutive naturals, for example, 2030808 + ... + 2030869.

It is an arithmetic number, because the mean of its divisors is an integer number (32493424).

Almost surely, 2^125911987 is an apocalyptic number.

125911987 is a deficient number, since it is larger than the sum of its proper divisors (4061709).

125911987 is an equidigital number, since it uses as much as digits as its factorization.

125911987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4061708.

The product of its digits is 45360, while the sum is 43.

The square root of 125911987 is about 11221.0510648513. The cubic root of 125911987 is about 501.2130373674.

The spelling of 125911987 in words is "one hundred twenty-five million, nine hundred eleven thousand, nine hundred eighty-seven".