20121271 has 2 divisors, whose sum is σ = 20121272. Its totient is φ = 20121270.

The previous prime is 20121193. The next prime is 20121281. The reversal of 20121271 is 17212102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20121271 - 2⁹ = 20120759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060635 + 10060636.

It is an arithmetic number, because the mean of its divisors is an integer number (10060636).

Almost surely, 2^20121271 is an apocalyptic number.

20121271 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121271 is an equidigital number, since it uses as much as digits as its factorization.

20121271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 20121271 is about 4485.6739738862. The cubic root of 20121271 is about 271.9892900555.

Adding to 20121271 its reverse (17212102), we get a palindrome (37333373).

The spelling of 20121271 in words is "twenty million, one hundred twenty-one thousand, two hundred seventy-one".