20210021111221 has 2 divisors, whose sum is σ = 20210021111222. Its totient is φ = 20210021111220.

The previous prime is 20210021111171. The next prime is 20210021111251. The reversal of 20210021111221 is 12211112001202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10259119316196 + 9950901795025 = 3202986^2 + 3154505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210021111221 is a prime.

It is a super-2 number, since 2×20210021111221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20210021111195 and 20210021111204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20210021111251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105010555610 + 10105010555611.

It is an arithmetic number, because the mean of its divisors is an integer number (10105010555611).

Almost surely, 2^{20210021111221} is an apocalyptic number.

It is an amenable number.

20210021111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210021111221 is an equidigital number, since it uses as much as digits as its factorization.

20210021111221 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 16.

Adding to 20210021111221 its reverse (12211112001202), we get a palindrome (32421133112423).

The spelling of 20210021111221 in words is "twenty trillion, two hundred ten billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".