21130411261 has 2 divisors, whose sum is σ = 21130411262. Its totient is φ = 21130411260.

The previous prime is 21130411193. The next prime is 21130411339. The reversal of 21130411261 is 16211403112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21063007161 + 67404100 = 145131^2 + 8210^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130411261 - 2¹³ = 21130403069 is a prime.

It is a super-2 number, since 2×21130411261² (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 (21130411661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565205630 + 10565205631.

It is an arithmetic number, because the mean of its divisors is an integer number (10565205631).

Almost surely, 2^21130411261 is an apocalyptic number.

It is an amenable number.

21130411261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130411261 is an equidigital number, since it uses as much as digits as its factorization.

21130411261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21130411261 its reverse (16211403112), we get a palindrome (37341814373).

The spelling of 21130411261 in words is "twenty-one billion, one hundred thirty million, four hundred eleven thousand, two hundred sixty-one".