21212021071 has 2 divisors, whose sum is σ = 21212021072. Its totient is φ = 21212021070.

The previous prime is 21212021041. The next prime is 21212021123. The reversal of 21212021071 is 17012021212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212021071 - 2⁷ = 21212020943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212021041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606010535 + 10606010536.

It is an arithmetic number, because the mean of its divisors is an integer number (10606010536).

Almost surely, 2^21212021071 is an apocalyptic number.

21212021071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212021071 is an equidigital number, since it uses as much as digits as its factorization.

21212021071 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 19.

Adding to 21212021071 its reverse (17012021212), we get a palindrome (38224042283).

The spelling of 21212021071 in words is "twenty-one billion, two hundred twelve million, twenty-one thousand, seventy-one".