21230221013 has 2 divisors, whose sum is σ = 21230221014. Its totient is φ = 21230221012.

The previous prime is 21230220961. The next prime is 21230221037. The reversal of 21230221013 is 31012203212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17316717649 + 3913503364 = 131593^2 + 62558^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230221013 - 2²⁶ = 21163112149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21230220982 and 21230221000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21230221043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615110506 + 10615110507.

It is an arithmetic number, because the mean of its divisors is an integer number (10615110507).

Almost surely, 2^21230221013 is an apocalyptic number.

It is an amenable number.

21230221013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230221013 is an equidigital number, since it uses as much as digits as its factorization.

21230221013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21230221013 its reverse (31012203212), we get a palindrome (52242424225).

The spelling of 21230221013 in words is "twenty-one billion, two hundred thirty million, two hundred twenty-one thousand, thirteen".