21110020121021 has 8 divisors (see below), whose sum is σ = 22773821904120. Its totient is φ = 19451926063872.

The previous prime is 21110020120997. The next prime is 21110020121087. The reversal of 21110020121021 is 12012102001112.

It can be written as a sum of positive squares in 4 ways, for example, as 1107568912921 + 20002451208100 = 1052411^2 + 4472410^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21110020121021 is a prime.

It is a super-2 number, since 2×21110020121021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110020120987 and 21110020121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110020321021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1426923800 + ... + 1426938593.

It is an arithmetic number, because the mean of its divisors is an integer number (2846727738015).

Almost surely, 2^{21110020121021} is an apocalyptic number.

It is an amenable number.

21110020121021 is a deficient number, since it is larger than the sum of its proper divisors (1663801783099).

21110020121021 is a wasteful number, since it uses less digits than its factorization.

21110020121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2853862975.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21110020121021 its reverse (12012102001112), we get a palindrome (33122122122133).

The spelling of 21110020121021 in words is "twenty-one trillion, one hundred ten billion, twenty million, one hundred twenty-one thousand, twenty-one".