21102021220021 has 8 divisors (see below), whose sum is σ = 24126056899200. Its totient is φ = 18080350845648.

The previous prime is 21102021220019. The next prime is 21102021220037. The reversal of 21102021220021 is 12002212020112.

It is a happy number.

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

It is not a de Polignac number, because 21102021220021 - 2¹ = 21102021220019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102021219977 and 21102021220004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102021220121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 591307081 + ... + 591342766.

It is an arithmetic number, because the mean of its divisors is an integer number (3015757112400).

Almost surely, 2^{21102021220021} is an apocalyptic number.

It is an amenable number.

21102021220021 is a deficient number, since it is larger than the sum of its proper divisors (3024035679179).

21102021220021 is a wasteful number, since it uses less digits than its factorization.

21102021220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182652403.

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

Adding to 21102021220021 its reverse (12002212020112), we get a palindrome (33104233240133).

The spelling of 21102021220021 in words is "twenty-one trillion, one hundred two billion, twenty-one million, two hundred twenty thousand, twenty-one".