51913318609 has 2 divisors, whose sum is σ = 51913318610. Its totient is φ = 51913318608.

The previous prime is 51913318603. The next prime is 51913318631. The reversal of 51913318609 is 90681331915.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40810060225 + 11103258384 = 202015^2 + 105372^2 .

It is a cyclic number.

It is not a de Polignac number, because 51913318609 - 2⁵ = 51913318577 is a prime.

It is not a weakly prime, because it can be changed into another prime (51913318603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25956659304 + 25956659305.

It is an arithmetic number, because the mean of its divisors is an integer number (25956659305).

Almost surely, 2^51913318609 is an apocalyptic number.

It is an amenable number.

51913318609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51913318609 is an equidigital number, since it uses as much as digits as its factorization.

51913318609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 46.

The spelling of 51913318609 in words is "fifty-one billion, nine hundred thirteen million, three hundred eighteen thousand, six hundred nine".