311212302221 has 4 divisors (see below), whose sum is σ = 329518908252. Its totient is φ = 292905696192.

The previous prime is 311212302173. The next prime is 311212302227. The reversal of 311212302221 is 122203212113.

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 261950499721 + 49261802500 = 511811^2 + 221950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311212302221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311212302193 and 311212302202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311212302227) 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, 9153302990 + ... + 9153303023.

It is an arithmetic number, because the mean of its divisors is an integer number (82379727063).

Almost surely, 2^311212302221 is an apocalyptic number.

It is an amenable number.

311212302221 is a deficient number, since it is larger than the sum of its proper divisors (18306606031).

311212302221 is a wasteful number, since it uses less digits than its factorization.

311212302221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18306606030.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 311212302221 its reverse (122203212113), we get a palindrome (433415514334).

The spelling of 311212302221 in words is "three hundred eleven billion, two hundred twelve million, three hundred two thousand, two hundred twenty-one".