21021013271 has 2 divisors, whose sum is σ = 21021013272. Its totient is φ = 21021013270.

The previous prime is 21021013267. The next prime is 21021013303. The reversal of 21021013271 is 17231012012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021013271 - 2² = 21021013267 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021013201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510506635 + 10510506636.

It is an arithmetic number, because the mean of its divisors is an integer number (10510506636).

Almost surely, 2^21021013271 is an apocalyptic number.

21021013271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021013271 is an equidigital number, since it uses as much as digits as its factorization.

21021013271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21021013271 its reverse (17231012012), we get a palindrome (38252025283).

The spelling of 21021013271 in words is "twenty-one billion, twenty-one million, thirteen thousand, two hundred seventy-one".