20420961271 has 2 divisors, whose sum is σ = 20420961272. Its totient is φ = 20420961270.

The previous prime is 20420961259. The next prime is 20420961287. The reversal of 20420961271 is 17216902402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20420961271 - 2²¹ = 20418864119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20420961241) 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, 10210480635 + 10210480636.

It is an arithmetic number, because the mean of its divisors is an integer number (10210480636).

Almost surely, 2^20420961271 is an apocalyptic number.

20420961271 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420961271 is an equidigital number, since it uses as much as digits as its factorization.

20420961271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 34.

The spelling of 20420961271 in words is "twenty billion, four hundred twenty million, nine hundred sixty-one thousand, two hundred seventy-one".