17987557009 has 2 divisors, whose sum is σ = 17987557010. Its totient is φ = 17987557008.

The previous prime is 17987556971. The next prime is 17987557019. The reversal of 17987557009 is 90075578971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9438705409 + 8548851600 = 97153^2 + 92460^2 .

It is a cyclic number.

It is not a de Polignac number, because 17987557009 - 2⁹ = 17987556497 is a prime.

It is not a weakly prime, because it can be changed into another prime (17987557019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8993778504 + 8993778505.

It is an arithmetic number, because the mean of its divisors is an integer number (8993778505).

Almost surely, 2^17987557009 is an apocalyptic number.

It is an amenable number.

17987557009 is a deficient number, since it is larger than the sum of its proper divisors (1).

17987557009 is an equidigital number, since it uses as much as digits as its factorization.

17987557009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5556600, while the sum is 58.

The spelling of 17987557009 in words is "seventeen billion, nine hundred eighty-seven million, five hundred fifty-seven thousand, nine".