21101130221 has 2 divisors, whose sum is σ = 21101130222. Its totient is φ = 21101130220.

The previous prime is 21101130209. The next prime is 21101130263. The reversal of 21101130221 is 12203110112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21100758121 + 372100 = 145261^2 + 610^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101130221 - 2¹⁸ = 21100868077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21101130196 and 21101130205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101330221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550565110 + 10550565111.

It is an arithmetic number, because the mean of its divisors is an integer number (10550565111).

Almost surely, 2^21101130221 is an apocalyptic number.

It is an amenable number.

21101130221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101130221 is an equidigital number, since it uses as much as digits as its factorization.

21101130221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21101130221 its reverse (12203110112), we get a palindrome (33304240333).

The spelling of 21101130221 in words is "twenty-one billion, one hundred one million, one hundred thirty thousand, two hundred twenty-one".