355 has 4 divisors (see below), whose sum is σ = 432. Its totient is φ = 280.

The previous prime is 353. The next prime is 359. The reversal of 355 is 553.

355 = 5² + 6² + ... + 10².

355 is nontrivially palindromic in base 9.

355 is an esthetic number in base 8 and base 9, because in such bases its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 553 = 7 ⋅79.

It is not a de Polignac number, because 355 - 2¹ = 353 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

355 is an undulating number in base 9.

It is a plaindrome in base 10, base 12 and base 15.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (353) 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 3 ways as a sum of consecutive naturals, for example, 31 + ... + 40.

It is an arithmetic number, because the mean of its divisors is an integer number (108).

2³⁵⁵ is an apocalyptic number.

355 is a deficient number, since it is larger than the sum of its proper divisors (77).

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

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

The sum of its prime factors is 76.

The product of its digits is 75, while the sum is 13.

The square root of 355 is about 18.8414436814. The cubic root of 355 is about 7.0806987511.

The spelling of 355 in words is "three hundred fifty-five", and thus it is an aban number and an oban number.