311918813 has 4 divisors (see below), whose sum is σ = 311979228. Its totient is φ = 311858400.

The previous prime is 311918791. The next prime is 311918821. The reversal of 311918813 is 318819113.

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 190081369 + 121837444 = 13787^2 + 11038^2 .

It is a cyclic number.

It is not a de Polignac number, because 311918813 - 2⁶ = 311918749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311918863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21656 + ... + 33057.

It is an arithmetic number, because the mean of its divisors is an integer number (77994807).

Almost surely, 2^311918813 is an apocalyptic number.

It is an amenable number.

311918813 is a deficient number, since it is larger than the sum of its proper divisors (60415).

311918813 is an equidigital number, since it uses as much as digits as its factorization.

311918813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60414.

The product of its digits is 5184, while the sum is 35.

The square root of 311918813 is about 17661.2234287435. The cubic root of 311918813 is about 678.1834539516.

It can be divided in two parts, 31191 and 8813, that added together give a palindrome (40004).

The spelling of 311918813 in words is "three hundred eleven million, nine hundred eighteen thousand, eight hundred thirteen".