21221110110121 has 4 divisors (see below), whose sum is σ = 22469410704852. Its totient is φ = 19972809515392.

The previous prime is 21221110110119. The next prime is 21221110110203. The reversal of 21221110110121 is 12101101112212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19096803860121 + 2124306250000 = 4369989^2 + 1457500^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221110110121 - 2¹ = 21221110110119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221110110095 and 21221110110104.

It is not an unprimeable number, because it can be changed into a prime (21221110117121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 624150297340 + ... + 624150297373.

It is an arithmetic number, because the mean of its divisors is an integer number (5617352676213).

Almost surely, 2^{21221110110121} is an apocalyptic number.

It is an amenable number.

21221110110121 is a deficient number, since it is larger than the sum of its proper divisors (1248300594731).

21221110110121 is a wasteful number, since it uses less digits than its factorization.

21221110110121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248300594730.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21221110110121 its reverse (12101101112212), we get a palindrome (33322211222333).

The spelling of 21221110110121 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred ten million, one hundred ten thousand, one hundred twenty-one".