21020221200021 has 16 divisors (see below), whose sum is σ = 28236159615744. Its totient is φ = 13908915282944.

The previous prime is 21020221200007. The next prime is 21020221200031. The reversal of 21020221200021 is 12000212202012.

It is a cyclic number.

It is not a de Polignac number, because 21020221200021 - 2⁷ = 21020221199893 is a prime.

It is a super-3 number, since 3×21020221200021³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020221200031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1670781 + ... + 6695666.

It is an arithmetic number, because the mean of its divisors is an integer number (1764759975984).

Almost surely, 2^{21020221200021} is an apocalyptic number.

It is an amenable number.

21020221200021 is a deficient number, since it is larger than the sum of its proper divisors (7215938415723).

21020221200021 is a wasteful number, since it uses less digits than its factorization.

21020221200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8372700.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020221200021 its reverse (12000212202012), we get a palindrome (33020433402033).

The spelling of 21020221200021 in words is "twenty-one trillion, twenty billion, two hundred twenty-one million, two hundred thousand, twenty-one".