17561340749 has 2 divisors, whose sum is σ = 17561340750. Its totient is φ = 17561340748.

The previous prime is 17561340701. The next prime is 17561340757. The reversal of 17561340749 is 94704316571.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10371996649 + 7189344100 = 101843^2 + 84790^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17561340749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17561342749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8780670374 + 8780670375.

It is an arithmetic number, because the mean of its divisors is an integer number (8780670375).

Almost surely, 2^17561340749 is an apocalyptic number.

It is an amenable number.

17561340749 is a deficient number, since it is larger than the sum of its proper divisors (1).

17561340749 is an equidigital number, since it uses as much as digits as its factorization.

17561340749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 635040, while the sum is 47.

The spelling of 17561340749 in words is "seventeen billion, five hundred sixty-one million, three hundred forty thousand, seven hundred forty-nine".