20313211021 has 2 divisors, whose sum is σ = 20313211022. Its totient is φ = 20313211020.

The previous prime is 20313211019. The next prime is 20313211031. The reversal of 20313211021 is 12011231302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18710409796 + 1602801225 = 136786^2 + 40035^2 .

It is a cyclic number.

It is not a de Polignac number, because 20313211021 - 2¹ = 20313211019 is a prime.

Together with 20313211019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20313210986 and 20313211004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20313211031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10156605510 + 10156605511.

It is an arithmetic number, because the mean of its divisors is an integer number (10156605511).

Almost surely, 2^20313211021 is an apocalyptic number.

It is an amenable number.

20313211021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20313211021 is an equidigital number, since it uses as much as digits as its factorization.

20313211021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 20313211021 its reverse (12011231302), we get a palindrome (32324442323).

The spelling of 20313211021 in words is "twenty billion, three hundred thirteen million, two hundred eleven thousand, twenty-one".