125128767661 has 4 divisors (see below), whose sum is σ = 125135741500. Its totient is φ = 125121793824.

The previous prime is 125128767619. The next prime is 125128767667. The reversal of 125128767661 is 166767821521.

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

It can be written as a sum of positive squares in 2 ways, for example, as 59436002025 + 65692765636 = 243795^2 + 256306^2 .

It is a cyclic number.

It is not a de Polignac number, because 125128767661 - 2¹¹ = 125128765613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 125128767599 and 125128767608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125128767667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3459936 + ... + 3495913.

It is an arithmetic number, because the mean of its divisors is an integer number (31283935375).

Almost surely, 2^125128767661 is an apocalyptic number.

It is an amenable number.

125128767661 is a deficient number, since it is larger than the sum of its proper divisors (6973839).

125128767661 is an equidigital number, since it uses as much as digits as its factorization.

125128767661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6973838.

The product of its digits is 1693440, while the sum is 52.

The spelling of 125128767661 in words is "one hundred twenty-five billion, one hundred twenty-eight million, seven hundred sixty-seven thousand, six hundred sixty-one".