311240211543221 has 2 divisors, whose sum is σ = 311240211543222. Its totient is φ = 311240211543220.

The previous prime is 311240211543193. The next prime is 311240211543299. The reversal of 311240211543221 is 122345112042113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 259870165599121 + 51370045944100 = 16120489^2 + 7167290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311240211543221 is a prime.

It is a super-2 number, since 2×311240211543221² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311240211549221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155620105771610 + 155620105771611.

It is an arithmetic number, because the mean of its divisors is an integer number (155620105771611).

Almost surely, 2^{311240211543221} is an apocalyptic number.

It is an amenable number.

311240211543221 is a deficient number, since it is larger than the sum of its proper divisors (1).

311240211543221 is an equidigital number, since it uses as much as digits as its factorization.

311240211543221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 311240211543221 its reverse (122345112042113), we get a palindrome (433585323585334).

The spelling of 311240211543221 in words is "three hundred eleven trillion, two hundred forty billion, two hundred eleven million, five hundred forty-three thousand, two hundred twenty-one".