20213111021 has 2 divisors, whose sum is σ = 20213111022. Its totient is φ = 20213111020.

The previous prime is 20213110997. The next prime is 20213111029. The reversal of 20213111021 is 12011131202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17302508521 + 2910602500 = 131539^2 + 53950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20213111021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20213110987 and 20213111005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20213111029) 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, 10106555510 + 10106555511.

It is an arithmetic number, because the mean of its divisors is an integer number (10106555511).

Almost surely, 2^20213111021 is an apocalyptic number.

It is an amenable number.

20213111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20213111021 is an equidigital number, since it uses as much as digits as its factorization.

20213111021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 20213111021 its reverse (12011131202), we get a palindrome (32224242223).

The spelling of 20213111021 in words is "twenty billion, two hundred thirteen million, one hundred eleven thousand, twenty-one".