21013312301221 has 2 divisors, whose sum is σ = 21013312301222. Its totient is φ = 21013312301220.

The previous prime is 21013312301207. The next prime is 21013312301237. The reversal of 21013312301221 is 12210321331012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20116247592996 + 897064708225 = 4485114^2 + 947135^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013312301221 - 2¹⁵ = 21013312268453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21013312301192 and 21013312301201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013312304221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506656150610 + 10506656150611.

It is an arithmetic number, because the mean of its divisors is an integer number (10506656150611).

Almost surely, 2^{21013312301221} is an apocalyptic number.

It is an amenable number.

21013312301221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013312301221 is an equidigital number, since it uses as much as digits as its factorization.

21013312301221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21013312301221 its reverse (12210321331012), we get a palindrome (33223633632233).

The spelling of 21013312301221 in words is "twenty-one trillion, thirteen billion, three hundred twelve million, three hundred one thousand, two hundred twenty-one".