311881 has 2 divisors, whose sum is σ = 311882. Its totient is φ = 311880.

The previous prime is 311869. The next prime is 311897. The reversal of 311881 is 188113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 265225 + 46656 = 515^2 + 216^2 .

It is a cyclic number.

It is not a de Polignac number, because 311881 - 2¹³ = 303689 is a prime.

It is a super-2 number, since 2×311881² = 194539516322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (311821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155940 + 155941.

It is an arithmetic number, because the mean of its divisors is an integer number (155941).

2³¹¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

311881 is a deficient number, since it is larger than the sum of its proper divisors (1).

311881 is an equidigital number, since it uses as much as digits as its factorization.

311881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 22.

The square root of 311881 is about 558.4630695042. The cubic root of 311881 is about 67.8156048116.

Adding to 311881 its reverse (188113), we get a palindrome (499994).

It can be divided in two parts, 31 and 1881, that multiplied together give a triangular number (58311 = T₃₄₁).

The spelling of 311881 in words is "three hundred eleven thousand, eight hundred eighty-one".