16945 has 4 divisors (see below), whose sum is σ = 20340. Its totient is φ = 13552.

The previous prime is 16943. The next prime is 16963. The reversal of 16945 is 54961.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12321 + 4624 = 111^2 + 68^2 .

It is a cyclic number.

It is not a de Polignac number, because 16945 - 2¹ = 16943 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (16943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1690 + ... + 1699.

It is an arithmetic number, because the mean of its divisors is an integer number (5085).

2¹⁶⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

16945 is a deficient number, since it is larger than the sum of its proper divisors (3395).

16945 is an equidigital number, since it uses as much as digits as its factorization.

16945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3394.

The product of its digits is 1080, while the sum is 25.

The square root of 16945 is about 130.1729618623. The cubic root of 16945 is about 25.6850564410.

It can be divided in two parts, 16 and 945, that added together give a square (961 = 31²).

The spelling of 16945 in words is "sixteen thousand, nine hundred forty-five".