345 has 8 divisors (see below), whose sum is σ = 576. Its totient is φ = 176.

The previous prime is 337. The next prime is 347. The reversal of 345 is 543.

345 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 345 - 2³ = 337 is a prime.

345 is an idoneal number.

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

It is a Curzon number.

It is a straight-line number, since its digits are in arithmetic progression.

It is a plaindrome in base 6, base 10, base 12 and base 16.

It is a nialpdrome in base 8.

It is a self number, because there is not a number n which added to its sum of digits gives 345.

It is not an unprimeable number, because it can be changed into a prime (347) 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 7 ways as a sum of consecutive naturals, for example, 4 + ... + 26.

It is an arithmetic number, because the mean of its divisors is an integer number (72).

It is an amenable number.

345 is a deficient number, since it is larger than the sum of its proper divisors (231).

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

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

The sum of its prime factors is 31.

The product of its digits is 60, while the sum is 12.

The square root of 345 is about 18.5741756210. The cubic root of 345 is about 7.0135790835.

Subtracting from 345 its sum of digits (12), we obtain a palindrome (333).

Adding to 345 its reverse (543), we get a palindrome (888).

The spelling of 345 in words is "three hundred forty-five", and thus it is an aban number.