21221012081201 has 2 divisors, whose sum is σ = 21221012081202. Its totient is φ = 21221012081200.

The previous prime is 21221012081147. The next prime is 21221012081237. The reversal of 21221012081201 is 10218021012212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14785409232400 + 6435602848801 = 3845180^2 + 2536849^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221012081201 - 2¹⁴ = 21221012064817 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221012084201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610506040600 + 10610506040601.

It is an arithmetic number, because the mean of its divisors is an integer number (10610506040601).

Almost surely, 2^{21221012081201} is an apocalyptic number.

It is an amenable number.

21221012081201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221012081201 is an equidigital number, since it uses as much as digits as its factorization.

21221012081201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 23.

Adding to 21221012081201 its reverse (10218021012212), we get a palindrome (31439033093413).

The spelling of 21221012081201 in words is "twenty-one trillion, two hundred twenty-one billion, twelve million, eighty-one thousand, two hundred one".