21230255381 has 2 divisors, whose sum is σ = 21230255382. Its totient is φ = 21230255380.

The previous prime is 21230255369. The next prime is 21230255393. The reversal of 21230255381 is 18355203212.

It is a balanced prime because it is at equal distance from previous prime (21230255369) and next prime (21230255393).

It can be written as a sum of positive squares in only one way, i.e., 17178296356 + 4051959025 = 131066^2 + 63655^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230255381 is a prime.

It is a super-2 number, since 2×21230255381² (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 (21230455381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615127690 + 10615127691.

It is an arithmetic number, because the mean of its divisors is an integer number (10615127691).

Almost surely, 2^21230255381 is an apocalyptic number.

It is an amenable number.

21230255381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230255381 is an equidigital number, since it uses as much as digits as its factorization.

21230255381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 32.

Adding to 21230255381 its reverse (18355203212), we get a palindrome (39585458593).

The spelling of 21230255381 in words is "twenty-one billion, two hundred thirty million, two hundred fifty-five thousand, three hundred eighty-one".