20345 has 8 divisors (see below), whose sum is σ = 26376. Its totient is φ = 14976.

The previous prime is 20341. The next prime is 20347. The reversal of 20345 is 54302.

20345 is nontrivially palindromic in base 2.

20345 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1024 + 19321 = 32^2 + 139^2 .

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

It is not a de Polignac number, because 20345 - 2² = 20341 is a prime.

It is a Duffinian number.

20345 is strictly pandigital in base 6.

It is not an unprimeable number, because it can be changed into a prime (20341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92 + ... + 221.

It is an arithmetic number, because the mean of its divisors is an integer number (3297).

2²⁰³⁴⁵ is an apocalyptic number.

It is an amenable number.

20345 is a deficient number, since it is larger than the sum of its proper divisors (6031).

20345 is a wasteful number, since it uses less digits than its factorization.

20345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331.

The product of its (nonzero) digits is 120, while the sum is 14.

The square root of 20345 is about 142.6359001093. The cubic root of 20345 is about 27.2993662275.

Adding to 20345 its reverse (54302), we get a palindrome (74647).

The spelling of 20345 in words is "twenty thousand, three hundred forty-five".