125558855521 has 4 divisors (see below), whose sum is σ = 136973296944. Its totient is φ = 114144414100.

The previous prime is 125558855509. The next prime is 125558855557.

125558855521 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 125558855521 - 2³⁵ = 91199117153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125558855581) 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, 5707220695 + ... + 5707220716.

It is an arithmetic number, because the mean of its divisors is an integer number (34243324236).

Almost surely, 2^125558855521 is an apocalyptic number.

125558855521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

125558855521 is a deficient number, since it is larger than the sum of its proper divisors (11414441423).

125558855521 is a wasteful number, since it uses less digits than its factorization.

125558855521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11414441422.

The product of its digits is 4000000, while the sum is 52.

The spelling of 125558855521 in words is "one hundred twenty-five billion, five hundred fifty-eight million, eight hundred fifty-five thousand, five hundred twenty-one".