21221212130105 has 12 divisors (see below), whose sum is σ = 27575018839980. Its totient is φ = 15671048956992.

The previous prime is 21221212130101. The next prime is 21221212130141. The reversal of 21221212130105 is 50103121212212.

It can be written as a sum of positive squares in 6 ways, for example, as 925141956649 + 20296070173456 = 961843^2 + 4505116^2 .

It is not a de Polignac number, because 21221212130105 - 2² = 21221212130101 is a prime.

It is a super-2 number, since 2×21221212130105² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21221212130101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12556929410 + ... + 12556931099.

It is an arithmetic number, because the mean of its divisors is an integer number (2297918236665).

Almost surely, 2^{21221212130105} is an apocalyptic number.

It is an amenable number.

21221212130105 is a deficient number, since it is larger than the sum of its proper divisors (6353806709875).

21221212130105 is a wasteful number, since it uses less digits than its factorization.

21221212130105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25113860540 (or 25113860527 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

Adding to 21221212130105 its reverse (50103121212212), we get a palindrome (71324333342317).

The spelling of 21221212130105 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred thirty thousand, one hundred five".