21030330123221 has 2 divisors, whose sum is σ = 21030330123222. Its totient is φ = 21030330123220.

The previous prime is 21030330123181. The next prime is 21030330123239. The reversal of 21030330123221 is 12232103303012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21009746482321 + 20583640900 = 4583639^2 + 143470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21030330123221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21030335123221) 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, 10515165061610 + 10515165061611.

It is an arithmetic number, because the mean of its divisors is an integer number (10515165061611).

Almost surely, 2^{21030330123221} is an apocalyptic number.

It is an amenable number.

21030330123221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030330123221 is an equidigital number, since it uses as much as digits as its factorization.

21030330123221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21030330123221 its reverse (12232103303012), we get a palindrome (33262433426233).

The spelling of 21030330123221 in words is "twenty-one trillion, thirty billion, three hundred thirty million, one hundred twenty-three thousand, two hundred twenty-one".