21011021002021 has 8 divisors (see below), whose sum is σ = 21654926979840. Its totient is φ = 20375317648368.

The previous prime is 21011021001881. The next prime is 21011021002043. The reversal of 21011021002021 is 12020012011012.

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 21011021002021 - 2¹¹ = 21011020999973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011021001992 and 21011021002010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011021002051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2050650841 + ... + 2050661086.

It is an arithmetic number, because the mean of its divisors is an integer number (2706865872480).

Almost surely, 2^{21011021002021} is an apocalyptic number.

It is an amenable number.

21011021002021 is a deficient number, since it is larger than the sum of its proper divisors (643905977819).

21011021002021 is a wasteful number, since it uses less digits than its factorization.

21011021002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4101312083.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21011021002021 its reverse (12020012011012), we get a palindrome (33031033013033).

The spelling of 21011021002021 in words is "twenty-one trillion, eleven billion, twenty-one million, two thousand, twenty-one".