21311230032221 has 2 divisors, whose sum is σ = 21311230032222. Its totient is φ = 21311230032220.

The previous prime is 21311230032133. The next prime is 21311230032311. The reversal of 21311230032221 is 12223003211312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21211680316996 + 99549715225 = 4605614^2 + 315515^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311230032221 - 2¹⁴ = 21311230015837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311230932221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655615016110 + 10655615016111.

It is an arithmetic number, because the mean of its divisors is an integer number (10655615016111).

Almost surely, 2^{21311230032221} is an apocalyptic number.

It is an amenable number.

21311230032221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311230032221 is an equidigital number, since it uses as much as digits as its factorization.

21311230032221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21311230032221 its reverse (12223003211312), we get a palindrome (33534233243533).

The spelling of 21311230032221 in words is "twenty-one trillion, three hundred eleven billion, two hundred thirty million, thirty-two thousand, two hundred twenty-one".