16816945 has 4 divisors (see below), whose sum is σ = 20180340. Its totient is φ = 13453552.

The previous prime is 16816939. The next prime is 16816951. The reversal of 16816945 is 54961861.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (16816939) and next prime (16816951).

It can be written as a sum of positive squares in 2 ways, for example, as 2985984 + 13830961 = 1728^2 + 3719^2 .

It is a cyclic number.

It is not a de Polignac number, because 16816945 - 2²³ = 8428337 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 16816898 and 16816907.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1681690 + ... + 1681699.

It is an arithmetic number, because the mean of its divisors is an integer number (5045085).

Almost surely, 2^16816945 is an apocalyptic number.

It is an amenable number.

16816945 is a deficient number, since it is larger than the sum of its proper divisors (3363395).

16816945 is an equidigital number, since it uses as much as digits as its factorization.

16816945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3363394.

The product of its digits is 51840, while the sum is 40.

The square root of 16816945 is about 4100.8468637588. The cubic root of 16816945 is about 256.2019128486.

The spelling of 16816945 in words is "sixteen million, eight hundred sixteen thousand, nine hundred forty-five".