20102100220021 has 2 divisors, whose sum is σ = 20102100220022. Its totient is φ = 20102100220020.

The previous prime is 20102100219967. The next prime is 20102100220031. The reversal of 20102100220021 is 12002200120102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20100750024996 + 1350195025 = 4483386^2 + 36745^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20102100220021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20102100219983 and 20102100220010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20102100220031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10051050110010 + 10051050110011.

It is an arithmetic number, because the mean of its divisors is an integer number (10051050110011).

Almost surely, 2^{20102100220021} is an apocalyptic number.

It is an amenable number.

20102100220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20102100220021 is an equidigital number, since it uses as much as digits as its factorization.

20102100220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20102100220021 its reverse (12002200120102), we get a palindrome (32104300340123).

The spelling of 20102100220021 in words is "twenty trillion, one hundred two billion, one hundred million, two hundred twenty thousand, twenty-one".