311323001221 has 4 divisors (see below), whose sum is σ = 317946894912. Its totient is φ = 304699107532.

The previous prime is 311323001173. The next prime is 311323001251. The reversal of 311323001221 is 122100323113.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311323001221 is a prime.

It is a super-2 number, since 2×311323001221² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311323001251) 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, 3311946775 + ... + 3311946868.

It is an arithmetic number, because the mean of its divisors is an integer number (79486723728).

Almost surely, 2^311323001221 is an apocalyptic number.

It is an amenable number.

311323001221 is a deficient number, since it is larger than the sum of its proper divisors (6623893691).

311323001221 is an equidigital number, since it uses as much as digits as its factorization.

311323001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6623893690.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 311323001221 its reverse (122100323113), we get a palindrome (433423324334).

The spelling of 311323001221 in words is "three hundred eleven billion, three hundred twenty-three million, one thousand, two hundred twenty-one".