311212111321 has 4 divisors (see below), whose sum is σ = 311213227792. Its totient is φ = 311210994852.

The previous prime is 311212111267. The next prime is 311212111369. The reversal of 311212111321 is 123111212113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 123111212113 = 31 ⋅3971329423.

It is a cyclic number.

It is not a de Polignac number, because 311212111321 - 2³¹ = 309064627673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311212111621) 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, 248590 + ... + 827176.

It is an arithmetic number, because the mean of its divisors is an integer number (77803306948).

Almost surely, 2^311212111321 is an apocalyptic number.

It is an amenable number.

311212111321 is a deficient number, since it is larger than the sum of its proper divisors (1116471).

311212111321 is an equidigital number, since it uses as much as digits as its factorization.

311212111321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116470.

The product of its digits is 72, while the sum is 19.

Adding to 311212111321 its reverse (123111212113), we get a palindrome (434323323434).

The spelling of 311212111321 in words is "three hundred eleven billion, two hundred twelve million, one hundred eleven thousand, three hundred twenty-one".