20211000221021 has 2 divisors, whose sum is σ = 20211000221022. Its totient is φ = 20211000221020.

The previous prime is 20211000221017. The next prime is 20211000221047. The reversal of 20211000221021 is 12012200011202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10199560005625 + 10011440215396 = 3193675^2 + 3164086^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211000221021 - 2² = 20211000221017 is a prime.

It is a super-2 number, since 2×20211000221021² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20211000220987 and 20211000221005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211000211021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105500110510 + 10105500110511.

It is an arithmetic number, because the mean of its divisors is an integer number (10105500110511).

Almost surely, 2^{20211000221021} is an apocalyptic number.

It is an amenable number.

20211000221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211000221021 is an equidigital number, since it uses as much as digits as its factorization.

20211000221021 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 14.

Adding to 20211000221021 its reverse (12012200011202), we get a palindrome (32223200232223).

The spelling of 20211000221021 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one thousand, twenty-one".