213111321217 has 2 divisors, whose sum is σ = 213111321218. Its totient is φ = 213111321216.

The previous prime is 213111321209. The next prime is 213111321347. The reversal of 213111321217 is 712123111312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209250438721 + 3860882496 = 457439^2 + 62136^2 .

It is a cyclic number.

It is not a de Polignac number, because 213111321217 - 2³ = 213111321209 is a prime.

It is a super-2 number, since 2×213111321217² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 213111321191 and 213111321200.

It is not a weakly prime, because it can be changed into another prime (213111322217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106555660608 + 106555660609.

It is an arithmetic number, because the mean of its divisors is an integer number (106555660609).

Almost surely, 2^213111321217 is an apocalyptic number.

It is an amenable number.

213111321217 is a deficient number, since it is larger than the sum of its proper divisors (1).

213111321217 is an equidigital number, since it uses as much as digits as its factorization.

213111321217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 25.

Adding to 213111321217 its reverse (712123111312), we get a palindrome (925234432529).

The spelling of 213111321217 in words is "two hundred thirteen billion, one hundred eleven million, three hundred twenty-one thousand, two hundred seventeen".