21321023102261 has 2 divisors, whose sum is σ = 21321023102262. Its totient is φ = 21321023102260.

The previous prime is 21321023102161. The next prime is 21321023102363. The reversal of 21321023102261 is 16220132012312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13047403670161 + 8273619432100 = 3612119^2 + 2876390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21321023102261 is a prime.

It is a super-2 number, since 2×21321023102261² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21321023102261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21321023102161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660511551130 + 10660511551131.

It is an arithmetic number, because the mean of its divisors is an integer number (10660511551131).

Almost surely, 2^{21321023102261} is an apocalyptic number.

It is an amenable number.

21321023102261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321023102261 is an equidigital number, since it uses as much as digits as its factorization.

21321023102261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 21321023102261 its reverse (16220132012312), we get a palindrome (37541155114573).

The spelling of 21321023102261 in words is "twenty-one trillion, three hundred twenty-one billion, twenty-three million, one hundred two thousand, two hundred sixty-one".