21201101321 has 2 divisors, whose sum is σ = 21201101322. Its totient is φ = 21201101320.

The previous prime is 21201101293. The next prime is 21201101333. The reversal of 21201101321 is 12310110212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11682367225 + 9518734096 = 108085^2 + 97564^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201101321 - 2²⁶ = 21133992457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201101296 and 21201101305.

It is not a weakly prime, because it can be changed into another prime (21201101371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600550660 + 10600550661.

It is an arithmetic number, because the mean of its divisors is an integer number (10600550661).

Almost surely, 2^21201101321 is an apocalyptic number.

It is an amenable number.

21201101321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201101321 is an equidigital number, since it uses as much as digits as its factorization.

21201101321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21201101321 its reverse (12310110212), we get a palindrome (33511211533).

The spelling of 21201101321 in words is "twenty-one billion, two hundred one million, one hundred one thousand, three hundred twenty-one".