21002021201021 has 4 divisors (see below), whose sum is σ = 24002309944032. Its totient is φ = 18001732458012.

The previous prime is 21002021201011. The next prime is 21002021201089. The reversal of 21002021201021 is 12010212020012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21002021201021 - 2²⁶ = 21001954092157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002021200987 and 21002021201005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002021201011) 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, 1500144371495 + ... + 1500144371508.

It is an arithmetic number, because the mean of its divisors is an integer number (6000577486008).

Almost surely, 2^{21002021201021} is an apocalyptic number.

It is an amenable number.

21002021201021 is a deficient number, since it is larger than the sum of its proper divisors (3000288743011).

21002021201021 is an equidigital number, since it uses as much as digits as its factorization.

21002021201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000288743010.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21002021201021 its reverse (12010212020012), we get a palindrome (33012233221033).

The spelling of 21002021201021 in words is "twenty-one trillion, two billion, twenty-one million, two hundred one thousand, twenty-one".