311212113221 has 4 divisors (see below), whose sum is σ = 311218323072. Its totient is φ = 311205903372.

The previous prime is 311212113211. The next prime is 311212113253. The reversal of 311212113221 is 122311212113.

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 an emirpimes, since its reverse is a distinct semiprime: 122311212113 = 859 ⋅142387907.

It is a cyclic number.

It is not a de Polignac number, because 311212113221 - 2¹⁸ = 311211851077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311212113193 and 311212113202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311212113211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3029135 + ... + 3130188.

It is an arithmetic number, because the mean of its divisors is an integer number (77804580768).

Almost surely, 2^311212113221 is an apocalyptic number.

It is an amenable number.

311212113221 is a deficient number, since it is larger than the sum of its proper divisors (6209851).

311212113221 is an equidigital number, since it uses as much as digits as its factorization.

311212113221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6209850.

The product of its digits is 144, while the sum is 20.

Adding to 311212113221 its reverse (122311212113), we get a palindrome (433523325334).

The spelling of 311212113221 in words is "three hundred eleven billion, two hundred twelve million, one hundred thirteen thousand, two hundred twenty-one".