21021212111017 has 2 divisors, whose sum is σ = 21021212111018. Its totient is φ = 21021212111016.

The previous prime is 21021212110999. The next prime is 21021212111051. The reversal of 21021212111017 is 71011121212012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13752386313241 + 7268825797776 = 3708421^2 + 2696076^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021212111017 - 2⁷ = 21021212110889 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021212171017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510606055508 + 10510606055509.

It is an arithmetic number, because the mean of its divisors is an integer number (10510606055509).

Almost surely, 2^{21021212111017} is an apocalyptic number.

It is an amenable number.

21021212111017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021212111017 is an equidigital number, since it uses as much as digits as its factorization.

21021212111017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 22.

Adding to 21021212111017 its reverse (71011121212012), we get a palindrome (92032333323029).

The spelling of 21021212111017 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, one hundred eleven thousand, seventeen".