51647579561 has 2 divisors, whose sum is σ = 51647579562. Its totient is φ = 51647579560.

The previous prime is 51647579539. The next prime is 51647579567. The reversal of 51647579561 is 16597574615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42160819561 + 9486760000 = 205331^2 + 97400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51647579561 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51647579497 and 51647579506.

It is not a weakly prime, because it can be changed into another prime (51647579567) 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, 25823789780 + 25823789781.

It is an arithmetic number, because the mean of its divisors is an integer number (25823789781).

Almost surely, 2^51647579561 is an apocalyptic number.

It is an amenable number.

51647579561 is a deficient number, since it is larger than the sum of its proper divisors (1).

51647579561 is an equidigital number, since it uses as much as digits as its factorization.

51647579561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7938000, while the sum is 56.

The spelling of 51647579561 in words is "fifty-one billion, six hundred forty-seven million, five hundred seventy-nine thousand, five hundred sixty-one".