21102303221 has 2 divisors, whose sum is σ = 21102303222. Its totient is φ = 21102303220.

The previous prime is 21102303169. The next prime is 21102303239. The reversal of 21102303221 is 12230320112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18553164100 + 2549139121 = 136210^2 + 50489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102303221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21102303221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102300221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551151610 + 10551151611.

It is an arithmetic number, because the mean of its divisors is an integer number (10551151611).

Almost surely, 2^21102303221 is an apocalyptic number.

It is an amenable number.

21102303221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102303221 is an equidigital number, since it uses as much as digits as its factorization.

21102303221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21102303221 its reverse (12230320112), we get a palindrome (33332623333).

The spelling of 21102303221 in words is "twenty-one billion, one hundred two million, three hundred three thousand, two hundred twenty-one".