51685561764329 has 2 divisors, whose sum is σ = 51685561764330. Its totient is φ = 51685561764328.

The previous prime is 51685561764259. The next prime is 51685561764427. The reversal of 51685561764329 is 92346716558615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42081791754304 + 9603770010025 = 6487048^2 + 3098995^2 .

It is a cyclic number.

It is not a de Polignac number, because 51685561764329 - 2²⁰ = 51685560715753 is a prime.

It is not a weakly prime, because it can be changed into another prime (51685561164329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25842780882164 + 25842780882165.

It is an arithmetic number, because the mean of its divisors is an integer number (25842780882165).

Almost surely, 2^{51685561764329} is an apocalyptic number.

It is an amenable number.

51685561764329 is a deficient number, since it is larger than the sum of its proper divisors (1).

51685561764329 is an equidigital number, since it uses as much as digits as its factorization.

51685561764329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592000, while the sum is 68.

The spelling of 51685561764329 in words is "fifty-one trillion, six hundred eighty-five billion, five hundred sixty-one million, seven hundred sixty-four thousand, three hundred twenty-nine".