21020012221021 has 8 divisors (see below), whose sum is σ = 23927919050304. Its totient is φ = 18278271496320.

The previous prime is 21020012221001. The next prime is 21020012221069. The reversal of 21020012221021 is 12012221002012.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21020012221021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020012220986 and 21020012221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020012221001) 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, 41541525876 + ... + 41541526381.

It is an arithmetic number, because the mean of its divisors is an integer number (2990989881288).

Almost surely, 2^{21020012221021} is an apocalyptic number.

It is an amenable number.

21020012221021 is a deficient number, since it is larger than the sum of its proper divisors (2907906829283).

21020012221021 is a wasteful number, since it uses less digits than its factorization.

21020012221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83083052291.

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

Adding to 21020012221021 its reverse (12012221002012), we get a palindrome (33032233223033).

The spelling of 21020012221021 in words is "twenty-one trillion, twenty billion, twelve million, two hundred twenty-one thousand, twenty-one".