1345 has 4 divisors (see below), whose sum is σ = 1620.
Its totient is φ = 1072.
The previous prime is 1327. The next prime is 1361. The reversal of 1345 is 5431.
1345 is an esthetic number in base 6, because in such base its adjacent digits differ by 1.
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 256 + 1089 = 16^2 + 33^2
It is a cyclic number.
It is not a de Polignac number, because 1345 - 27 = 1217 is a prime.
It is a plaindrome in base 10.
It is a nialpdrome in base 12 and base 16.
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, 130 + ... + 139.
It is an arithmetic number, because the mean of its divisors is an integer number (405).
It is a Proth number, since it is equal to 21 ⋅ 26 + 1 and 21 < 26.
21345 is an apocalyptic number.
It is an amenable number.
1345 is a deficient number, since it is larger than the sum of its proper divisors (275).
1345 is an equidigital number, since it uses as much as digits as its factorization.
1345 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 274.
The product of its digits is 60, while the sum is 13.
The square root of 1345 is about 36.6742416418.
The cubic root of 1345 is about 11.0384330549.
Adding to 1345 its reverse (5431), we get a palindrome (6776).
It can be divided in two parts, 13 and 45, that multiplied together give a palindrome (585).
The spelling of 1345 in words is "one thousand, three hundred forty-five".