51660505609 has 2 divisors, whose sum is σ = 51660505610. Its totient is φ = 51660505608.

The previous prime is 51660505583. The next prime is 51660505649. The reversal of 51660505609 is 90650506615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34883779984 + 16776725625 = 186772^2 + 129525^2 .

It is a cyclic number.

It is not a de Polignac number, because 51660505609 - 2²⁷ = 51526287881 is a prime.

It is not a weakly prime, because it can be changed into another prime (51660505649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25830252804 + 25830252805.

It is an arithmetic number, because the mean of its divisors is an integer number (25830252805).

Almost surely, 2^51660505609 is an apocalyptic number.

It is an amenable number.

51660505609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51660505609 is an equidigital number, since it uses as much as digits as its factorization.

51660505609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243000, while the sum is 43.

The spelling of 51660505609 in words is "fifty-one billion, six hundred sixty million, five hundred five thousand, six hundred nine".