311221313 has 16 divisors (see below), whose sum is σ = 338760576. Its totient is φ = 284217600.

The previous prime is 311221289. The next prime is 311221331. The reversal of 311221313 is 313122113.

It is a cyclic number.

It is not a de Polignac number, because 311221313 - 2¹² = 311217217 is a prime.

It is a super-3 number, since 3×311221313³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 311221291 and 311221300.

It is not an unprimeable number, because it can be changed into a prime (311221343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 775913 + ... + 776313.

It is an arithmetic number, because the mean of its divisors is an integer number (21172536).

Almost surely, 2^311221313 is an apocalyptic number.

It is an amenable number.

311221313 is a deficient number, since it is larger than the sum of its proper divisors (27539263).

311221313 is a wasteful number, since it uses less digits than its factorization.

311221313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904.

The product of its digits is 108, while the sum is 17.

The square root of 311221313 is about 17641.4657270874. The cubic root of 311221313 is about 677.6775680497.

Adding to 311221313 its reverse (313122113), we get a palindrome (624343426).

The spelling of 311221313 in words is "three hundred eleven million, two hundred twenty-one thousand, three hundred thirteen".