16659919 has 2 divisors, whose sum is σ = 16659920. Its totient is φ = 16659918.

The previous prime is 16659917. The next prime is 16659931. The reversal of 16659919 is 91995661.

It is a weak prime.

It is an emirp because it is prime and its reverse (91995661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16659919 - 2¹ = 16659917 is a prime.

It is a super-2 number, since 2×16659919² = 555105802173122, which contains 22 as substring.

Together with 16659917, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16659911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8329959 + 8329960.

It is an arithmetic number, because the mean of its divisors is an integer number (8329960).

Almost surely, 2^16659919 is an apocalyptic number.

16659919 is a deficient number, since it is larger than the sum of its proper divisors (1).

16659919 is an equidigital number, since it uses as much as digits as its factorization.

16659919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 131220, while the sum is 46.

The square root of 16659919 is about 4081.6564039615. The cubic root of 16659919 is about 255.4020008073.

It can be divided in two parts, 16659 and 919, that added together give a triangular number (17578 = T₁₈₇).

The spelling of 16659919 in words is "sixteen million, six hundred fifty-nine thousand, nine hundred nineteen".