17491649509 has 2 divisors, whose sum is σ = 17491649510. Its totient is φ = 17491649508.

The previous prime is 17491649507. The next prime is 17491649551. The reversal of 17491649509 is 90594619471.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14227241284 + 3264408225 = 119278^2 + 57135^2 .

It is a cyclic number.

It is not a de Polignac number, because 17491649509 - 2¹ = 17491649507 is a prime.

Together with 17491649507, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 17491649509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17491649507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8745824754 + 8745824755.

It is an arithmetic number, because the mean of its divisors is an integer number (8745824755).

Almost surely, 2^17491649509 is an apocalyptic number.

It is an amenable number.

17491649509 is a deficient number, since it is larger than the sum of its proper divisors (1).

17491649509 is an equidigital number, since it uses as much as digits as its factorization.

17491649509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2449440, while the sum is 55.

The spelling of 17491649509 in words is "seventeen billion, four hundred ninety-one million, six hundred forty-nine thousand, five hundred nine".