125686619581 has 2 divisors, whose sum is σ = 125686619582. Its totient is φ = 125686619580.

The previous prime is 125686619567. The next prime is 125686619599. The reversal of 125686619581 is 185916686521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104694956356 + 20991663225 = 323566^2 + 144885^2 .

It is a cyclic number.

It is not a de Polignac number, because 125686619581 - 2⁷ = 125686619453 is a prime.

It is a super-2 number, since 2×125686619581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125686619281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62843309790 + 62843309791.

It is an arithmetic number, because the mean of its divisors is an integer number (62843309791).

Almost surely, 2^125686619581 is an apocalyptic number.

It is an amenable number.

125686619581 is a deficient number, since it is larger than the sum of its proper divisors (1).

125686619581 is an equidigital number, since it uses as much as digits as its factorization.

125686619581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6220800, while the sum is 58.

The spelling of 125686619581 in words is "one hundred twenty-five billion, six hundred eighty-six million, six hundred nineteen thousand, five hundred eighty-one".