21230255213 has 2 divisors, whose sum is σ = 21230255214. Its totient is φ = 21230255212.

The previous prime is 21230255191. The next prime is 21230255239. The reversal of 21230255213 is 31255203212.

It is a happy number.

It is an a-pointer prime, because the next prime (21230255239) can be obtained adding 21230255213 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19332955849 + 1897299364 = 139043^2 + 43558^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230255213 - 2¹⁰ = 21230254189 is a prime.

It is a super-2 number, since 2×21230255213² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21230252213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615127606 + 10615127607.

It is an arithmetic number, because the mean of its divisors is an integer number (10615127607).

Almost surely, 2^21230255213 is an apocalyptic number.

It is an amenable number.

21230255213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230255213 is an equidigital number, since it uses as much as digits as its factorization.

21230255213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21230255213 its reverse (31255203212), we get a palindrome (52485458425).

The spelling of 21230255213 in words is "twenty-one billion, two hundred thirty million, two hundred fifty-five thousand, two hundred thirteen".