19694665724137 has 2 divisors, whose sum is σ = 19694665724138. Its totient is φ = 19694665724136.

The previous prime is 19694665724051. The next prime is 19694665724141. The reversal of 19694665724137 is 73142756649691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14543018687961 + 5151647036176 = 3813531^2 + 2269724^2 .

It is a cyclic number.

It is not a de Polignac number, because 19694665724137 - 2⁷ = 19694665724009 is a prime.

It is not a weakly prime, because it can be changed into another prime (19694665724837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9847332862068 + 9847332862069.

It is an arithmetic number, because the mean of its divisors is an integer number (9847332862069).

Almost surely, 2^{19694665724137} is an apocalyptic number.

It is an amenable number.

19694665724137 is a deficient number, since it is larger than the sum of its proper divisors (1).

19694665724137 is an equidigital number, since it uses as much as digits as its factorization.

19694665724137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 411505920, while the sum is 70.

The spelling of 19694665724137 in words is "nineteen trillion, six hundred ninety-four billion, six hundred sixty-five million, seven hundred twenty-four thousand, one hundred thirty-seven".