51511668728569 has 27 divisors (see below), whose sum is σ = 60150825358533. Its totient is φ = 43984697981112.

The previous prime is 51511668728557. The next prime is 51511668728573. The reversal of 51511668728569 is 96582786611515.

The square root of 51511668728569 is 7177163.

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

It is not a de Polignac number, because 51511668728569 - 2⁷ = 51511668728441 is a prime.

It is a super-2 number, since 2×51511668728569² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51511668728498 and 51511668728507.

It is not an unprimeable number, because it can be changed into a prime (51511668728369) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 14217958092 + ... + 14217961714.

Almost surely, 2^{51511668728569} is an apocalyptic number.

51511668728569 is the 7177163-rd square number.

51511668728569 is the 3588582-nd centered octagonal number.

It is an amenable number.

51511668728569 is a deficient number, since it is larger than the sum of its proper divisors (8639156629964).

51511668728569 is an frugal number, since it uses more digits than its factorization.

51511668728569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7826 (or 3913 counting only the distinct ones).

The product of its digits is 217728000, while the sum is 70.

The spelling of 51511668728569 in words is "fifty-one trillion, five hundred eleven billion, six hundred sixty-eight million, seven hundred twenty-eight thousand, five hundred sixty-nine".