1681936640513 has 2 divisors, whose sum is σ = 1681936640514. Its totient is φ = 1681936640512.

The previous prime is 1681936640473. The next prime is 1681936640609. The reversal of 1681936640513 is 3150466391861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1495954040464 + 185982600049 = 1223092^2 + 431257^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681936640513 - 2¹⁰ = 1681936639489 is a prime.

It is not a weakly prime, because it can be changed into another prime (1681936649513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840968320256 + 840968320257.

It is an arithmetic number, because the mean of its divisors is an integer number (840968320257).

Almost surely, 2^{1681936640513} is an apocalyptic number.

It is an amenable number.

1681936640513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681936640513 is an equidigital number, since it uses as much as digits as its factorization.

1681936640513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2799360, while the sum is 53.

The spelling of 1681936640513 in words is "one trillion, six hundred eighty-one billion, nine hundred thirty-six million, six hundred forty thousand, five hundred thirteen".