17980661 has 2 divisors, whose sum is σ = 17980662. Its totient is φ = 17980660.

The previous prime is 17980657. The next prime is 17980709. The reversal of 17980661 is 16608971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16240900 + 1739761 = 4030^2 + 1319^2 .

It is a cyclic number.

It is not a de Polignac number, because 17980661 - 2² = 17980657 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17980861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8990330 + 8990331.

It is an arithmetic number, because the mean of its divisors is an integer number (8990331).

Almost surely, 2^17980661 is an apocalyptic number.

It is an amenable number.

17980661 is a deficient number, since it is larger than the sum of its proper divisors (1).

17980661 is an equidigital number, since it uses as much as digits as its factorization.

17980661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 17980661 is about 4240.3609516172. The cubic root of 17980661 is about 261.9802492735.

The spelling of 17980661 in words is "seventeen million, nine hundred eighty thousand, six hundred sixty-one".