545 has 4 divisors (see below), whose sum is σ = 660.
Its totient is φ = 432.
The previous prime is 541. The next prime is 547.
It can be divided in two parts, 5 and 45, that multiplied together give a square (225 = 152).
545 = 162 + 172.
545 is nontrivially palindromic in base 10.
545 is an esthetic number in base 10 and base 11, because in such bases 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 289 + 256 = 17^2 + 16^2
It is a cyclic number.
It is not a de Polignac number, because 545 - 22 = 541 is a prime.
It is an alternating number because its digits alternate between odd and even.
545 is an undulating number in base 10.
545 is a modest number, since divided by 45 gives 5 as remainder.
It is a Curzon number.
It is a plaindrome in base 11 and base 14.
It is a nialpdrome in base 9 and base 16.
It is not an unprimeable number, because it can be changed into a prime (541) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50 + ... + 59.
It is an arithmetic number, because the mean of its divisors is an integer number (165).
It is a Proth number, since it is equal to 17 ⋅ 25 + 1 and 17 < 25.
545 is the 17-th centered square number.
It is an amenable number.
545 is a deficient number, since it is larger than the sum of its proper divisors (115).
545 is a wasteful number, since it uses less digits than its factorization.
545 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 114.
The product of its digits is 100, while the sum is 14.
The square root of 545 is about 23.3452350599.
The cubic root of 545 is about 8.1683091703.
The spelling of 545 in words is "five hundred forty-five", and thus it is an aban number.