17945 has 8 divisors (see below), whose sum is σ = 22344. Its totient is φ = 13824.

The previous prime is 17939. The next prime is 17957. The reversal of 17945 is 54971.

It can be written as a sum of positive squares in 4 ways, for example, as 4489 + 13456 = 67^2 + 116^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 17945 - 2⁴ = 17929 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137 + ... + 233.

It is an arithmetic number, because the mean of its divisors is an integer number (2793).

2¹⁷⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

17945 is a deficient number, since it is larger than the sum of its proper divisors (4399).

17945 is an equidigital number, since it uses as much as digits as its factorization.

17945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139.

The product of its digits is 1260, while the sum is 26.

The square root of 17945 is about 133.9589489359. The cubic root of 17945 is about 26.1806939724.

Adding to 17945 its sum of digits (26), we get a palindrome (17971).

The spelling of 17945 in words is "seventeen thousand, nine hundred forty-five".