311211211021 has 4 divisors (see below), whose sum is σ = 311214055932. Its totient is φ = 311208366112.

The previous prime is 311211210977. The next prime is 311211211049. The reversal of 311211211021 is 120112112113.

It is a happy number.

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 302127214921 + 9083996100 = 549661^2 + 95310^2 .

It is a cyclic number.

It is not a de Polignac number, because 311211211021 - 2⁹ = 311211210509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311211210986 and 311211211004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311211211321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1251520 + ... + 1479433.

It is an arithmetic number, because the mean of its divisors is an integer number (77803513983).

Almost surely, 2^311211211021 is an apocalyptic number.

It is an amenable number.

311211211021 is a deficient number, since it is larger than the sum of its proper divisors (2844911).

311211211021 is a wasteful number, since it uses less digits than its factorization.

311211211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2844910.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 311211211021 its reverse (120112112113), we get a palindrome (431323323134).

The spelling of 311211211021 in words is "three hundred eleven billion, two hundred eleven million, two hundred eleven thousand, twenty-one".