20210321221 has 2 divisors, whose sum is σ = 20210321222. Its totient is φ = 20210321220.

The previous prime is 20210321207. The next prime is 20210321227. The reversal of 20210321221 is 12212301202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15502989121 + 4707332100 = 124511^2 + 68610^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210321221 - 2⁹ = 20210320709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20210321195 and 20210321204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20210321227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105160610 + 10105160611.

It is an arithmetic number, because the mean of its divisors is an integer number (10105160611).

Almost surely, 2^20210321221 is an apocalyptic number.

It is an amenable number.

20210321221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210321221 is an equidigital number, since it uses as much as digits as its factorization.

20210321221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 20210321221 its reverse (12212301202), we get a palindrome (32422622423).

The spelling of 20210321221 in words is "twenty billion, two hundred ten million, three hundred twenty-one thousand, two hundred twenty-one".