21168213167 has 2 divisors, whose sum is σ = 21168213168. Its totient is φ = 21168213166.

The previous prime is 21168213163. The next prime is 21168213239. The reversal of 21168213167 is 76131286112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21168213167 - 2² = 21168213163 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21168213167.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21168213163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10584106583 + 10584106584.

It is an arithmetic number, because the mean of its divisors is an integer number (10584106584).

Almost surely, 2^21168213167 is an apocalyptic number.

21168213167 is a deficient number, since it is larger than the sum of its proper divisors (1).

21168213167 is an equidigital number, since it uses as much as digits as its factorization.

21168213167 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 38.

Adding to 21168213167 its reverse (76131286112), we get a palindrome (97299499279).

The spelling of 21168213167 in words is "twenty-one billion, one hundred sixty-eight million, two hundred thirteen thousand, one hundred sixty-seven".