16988509 has 2 divisors, whose sum is σ = 16988510. Its totient is φ = 16988508.

The previous prime is 16988501. The next prime is 16988549. The reversal of 16988509 is 90588961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 5189284 = 3435^2 + 2278^2 .

It is an emirp because it is prime and its reverse (90588961) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16988509 - 2³ = 16988501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16988501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8494254 + 8494255.

It is an arithmetic number, because the mean of its divisors is an integer number (8494255).

Almost surely, 2^16988509 is an apocalyptic number.

It is an amenable number.

16988509 is a deficient number, since it is larger than the sum of its proper divisors (1).

16988509 is an equidigital number, since it uses as much as digits as its factorization.

16988509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 16988509 is about 4121.7119016253. The cubic root of 16988509 is about 257.0702115040.

The spelling of 16988509 in words is "sixteen million, nine hundred eighty-eight thousand, five hundred nine".