125111471521 has 3 divisors (see below), whose sum is σ = 125111825233. Its totient is φ = 125111117810.

The previous prime is 125111471509. The next prime is 125111471557. The reversal of 125111471521 is 125174111521.

It is a happy number.

The square root of 125111471521 is 353711.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 125174111521 = 2753 ⋅45468257.

It is not a de Polignac number, because 125111471521 - 2¹⁷ = 125111340449 is a prime.

It is a super-2 number, since 2×125111471521² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125111271521) 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 2 ways as a sum of consecutive naturals, for example, 176856 + ... + 530566.

Almost surely, 2^125111471521 is an apocalyptic number.

125111471521 is the 353711-st square number.

125111471521 is the 176856-th centered octagonal number.

It is an amenable number.

125111471521 is a deficient number, since it is larger than the sum of its proper divisors (353712).

125111471521 is an frugal number, since it uses more digits than its factorization.

125111471521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707422 (or 353711 counting only the distinct ones).

The product of its digits is 2800, while the sum is 31.

The spelling of 125111471521 in words is "one hundred twenty-five billion, one hundred eleven million, four hundred seventy-one thousand, five hundred twenty-one".