16809943 has 2 divisors, whose sum is σ = 16809944. Its totient is φ = 16809942.

The previous prime is 16809931. The next prime is 16809971. The reversal of 16809943 is 34990861.

It is a weak prime.

It is an emirp because it is prime and its reverse (34990861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16809943 - 2¹³ = 16801751 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16809896 and 16809905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16809913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8404971 + 8404972.

It is an arithmetic number, because the mean of its divisors is an integer number (8404972).

Almost surely, 2^16809943 is an apocalyptic number.

16809943 is a deficient number, since it is larger than the sum of its proper divisors (1).

16809943 is an equidigital number, since it uses as much as digits as its factorization.

16809943 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 16809943 is about 4099.9930487746. The cubic root of 16809943 is about 256.1663500114.

The spelling of 16809943 in words is "sixteen million, eight hundred nine thousand, nine hundred forty-three".