19713634649 has 2 divisors, whose sum is σ = 19713634650. Its totient is φ = 19713634648.

The previous prime is 19713634631. The next prime is 19713634687. The reversal of 19713634649 is 94643631791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13907956624 + 5805678025 = 117932^2 + 76195^2 .

It is an emirp because it is prime and its reverse (94643631791) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19713634649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19713634649.

It is not a weakly prime, because it can be changed into another prime (19713634849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9856817324 + 9856817325.

It is an arithmetic number, because the mean of its divisors is an integer number (9856817325).

Almost surely, 2^19713634649 is an apocalyptic number.

It is an amenable number.

19713634649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19713634649 is an equidigital number, since it uses as much as digits as its factorization.

19713634649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 53.

The spelling of 19713634649 in words is "nineteen billion, seven hundred thirteen million, six hundred thirty-four thousand, six hundred forty-nine".