20213101021 has 2 divisors, whose sum is σ = 20213101022. Its totient is φ = 20213101020.

The previous prime is 20213101009. The next prime is 20213101061. The reversal of 20213101021 is 12010131202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16581712900 + 3631388121 = 128770^2 + 60261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20213101021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20213100992 and 20213101010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20213101061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10106550510 + 10106550511.

It is an arithmetic number, because the mean of its divisors is an integer number (10106550511).

Almost surely, 2^20213101021 is an apocalyptic number.

It is an amenable number.

20213101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20213101021 is an equidigital number, since it uses as much as digits as its factorization.

20213101021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 20213101021 its reverse (12010131202), we get a palindrome (32223232223).

The spelling of 20213101021 in words is "twenty billion, two hundred thirteen million, one hundred one thousand, twenty-one".