21130101021221 has 2 divisors, whose sum is σ = 21130101021222. Its totient is φ = 21130101021220.

The previous prime is 21130101021217. The next prime is 21130101021229. The reversal of 21130101021221 is 12212010103112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15204649670596 + 5925451350625 = 3899314^2 + 2434225^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130101021221 - 2² = 21130101021217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21130101021221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130101021229) 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, 10565050510610 + 10565050510611.

It is an arithmetic number, because the mean of its divisors is an integer number (10565050510611).

Almost surely, 2^{21130101021221} is an apocalyptic number.

It is an amenable number.

21130101021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130101021221 is an equidigital number, since it uses as much as digits as its factorization.

21130101021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21130101021221 its reverse (12212010103112), we get a palindrome (33342111124333).

The spelling of 21130101021221 in words is "twenty-one trillion, one hundred thirty billion, one hundred one million, twenty-one thousand, two hundred twenty-one".