125428979521 has 2 divisors, whose sum is σ = 125428979522. Its totient is φ = 125428979520.

The previous prime is 125428979483. The next prime is 125428979531. The reversal of 125428979521 is 125979824521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117172713025 + 8256266496 = 342305^2 + 90864^2 .

It is a cyclic number.

It is not a de Polignac number, because 125428979521 - 2¹³ = 125428971329 is a prime.

It is not a weakly prime, because it can be changed into another prime (125428979531) 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 as a sum of consecutive naturals, namely, 62714489760 + 62714489761.

It is an arithmetic number, because the mean of its divisors is an integer number (62714489761).

Almost surely, 2^125428979521 is an apocalyptic number.

It is an amenable number.

125428979521 is a deficient number, since it is larger than the sum of its proper divisors (1).

125428979521 is an equidigital number, since it uses as much as digits as its factorization.

125428979521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3628800, while the sum is 55.

The spelling of 125428979521 in words is "one hundred twenty-five billion, four hundred twenty-eight million, nine hundred seventy-nine thousand, five hundred twenty-one".