51616651656561 has 16 divisors (see below), whose sum is σ = 70590791927040. Its totient is φ = 33530626095120.

The previous prime is 51616651656529. The next prime is 51616651656641. The reversal of 51616651656561 is 16565615661615.

It is a happy number.

It is not a de Polignac number, because 51616651656561 - 2⁵ = 51616651656529 is a prime.

It is a super-2 number, since 2×51616651656561² (a number of 28 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 51616651656495 and 51616651656504.

It is not an unprimeable number, because it can be changed into a prime (51616651656761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 477426955 + ... + 477535056.

It is an arithmetic number, because the mean of its divisors is an integer number (4411924495440).

Almost surely, 2^{51616651656561} is an apocalyptic number.

It is an amenable number.

51616651656561 is a deficient number, since it is larger than the sum of its proper divisors (18974140270479).

51616651656561 is a wasteful number, since it uses less digits than its factorization.

51616651656561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 954962476.

The product of its digits is 29160000, while the sum is 60.

The spelling of 51616651656561 in words is "fifty-one trillion, six hundred sixteen billion, six hundred fifty-one million, six hundred fifty-six thousand, five hundred sixty-one".