311 has 2 divisors, whose sum is σ = 312. Its totient is φ = 310.

The previous prime is 307. The next prime is 313. The reversal of 311 is 113.

It is a strong prime.

311 is a truncatable prime.

It is an emirp because it is prime and its reverse (113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 311 - 2^{2} = 307 is a prime.

Together with 313, it forms a pair of twin primes.

It is a Chen prime.

311 is a modest number, since divided by 11 gives 3 as remainder.

It is a plaindrome in base 6, base 8, base 13, base 15 and base 16.

It is a nialpdrome in base 5 and base 10.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 295 and 304.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155 + 156.

It is an arithmetic number, because the mean of its divisors is an integer number (156).

311 is a deficient number, since it is larger than the sum of its proper divisors (1).

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

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

The product of its digits is 3, while the sum is 5.

The square root of 311 is about 17.6351920885. The cubic root of 311 is about 6.7751689523.

Adding to 311 its reverse (113), we get a palindrome (424).

It can be divided in two parts, 31 and 1, that added together give a 5-th power (32 = 2^{5}).

The spelling of 311 in words is "three hundred eleven", and thus it is an aban number, an iban number, and an oban number.

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