21111111111317 has 2 divisors, whose sum is σ = 21111111111318. Its totient is φ = 21111111111316.

The previous prime is 21111111111313. The next prime is 21111111111359. The reversal of 21111111111317 is 71311111111112.

It is a m-pointer prime, because the next prime (21111111111359) can be obtained adding 21111111111317 to its product of digits (42).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12144116795281 + 8966994316036 = 3484841^2 + 2994494^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111111111317 - 2² = 21111111111313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111111111292 and 21111111111301.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111111111313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555555555658 + 10555555555659.

It is an arithmetic number, because the mean of its divisors is an integer number (10555555555659).

Almost surely, 2^{21111111111317} is an apocalyptic number.

It is an amenable number.

21111111111317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111111111317 is an equidigital number, since it uses as much as digits as its factorization.

21111111111317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42, while the sum is 23.

Adding to 21111111111317 its reverse (71311111111112), we get a palindrome (92422222222429).

The spelling of 21111111111317 in words is "twenty-one trillion, one hundred eleven billion, one hundred eleven million, one hundred eleven thousand, three hundred seventeen".