21220121002021 has 8 divisors (see below), whose sum is σ = 21222763271424. Its totient is φ = 21217478924400.

The previous prime is 21220121002019. The next prime is 21220121002027. The reversal of 21220121002021 is 12020012102212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21220121002021 - 2¹ = 21220121002019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220121001986 and 21220121002004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220121002027) 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, 388285320 + ... + 388339966.

It is an arithmetic number, because the mean of its divisors is an integer number (2652845408928).

Almost surely, 2^{21220121002021} is an apocalyptic number.

It is an amenable number.

21220121002021 is a deficient number, since it is larger than the sum of its proper divisors (2642269403).

21220121002021 is a wasteful number, since it uses less digits than its factorization.

21220121002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95891.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21220121002021 its reverse (12020012102212), we get a palindrome (33240133104233).

The spelling of 21220121002021 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two thousand, twenty-one".