125687644085 has 4 divisors (see below), whose sum is σ = 150825172908. Its totient is φ = 100550115264.

The previous prime is 125687644057. The next prime is 125687644087. The reversal of 125687644085 is 580446786521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 580446786521 = 7 ⋅82920969503.

It can be written as a sum of positive squares in 2 ways, for example, as 53924735089 + 71762908996 = 232217^2 + 267886^2 .

It is a cyclic number.

It is not a de Polignac number, because 125687644085 - 2¹⁰ = 125687643061 is a prime.

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 125687644085.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125687644087) 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, 12568764404 + ... + 12568764413.

It is an arithmetic number, because the mean of its divisors is an integer number (37706293227).

Almost surely, 2^125687644085 is an apocalyptic number.

It is an amenable number.

125687644085 is a deficient number, since it is larger than the sum of its proper divisors (25137528823).

125687644085 is an equidigital number, since it uses as much as digits as its factorization.

125687644085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25137528822.

The product of its (nonzero) digits is 12902400, while the sum is 56.

The spelling of 125687644085 in words is "one hundred twenty-five billion, six hundred eighty-seven million, six hundred forty-four thousand, eighty-five".