21112020021 has 8 divisors (see below), whose sum is σ = 28488509280. Its totient is φ = 13905105392.

The previous prime is 21112020019. The next prime is 21112020067. The reversal of 21112020021 is 12002021112.

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 21112020021 - 2¹ = 21112020019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112019979 and 21112020006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112020011) 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, 42393366 + ... + 42393863.

It is an arithmetic number, because the mean of its divisors is an integer number (3561063660).

Almost surely, 2^21112020021 is an apocalyptic number.

It is an amenable number.

21112020021 is a deficient number, since it is larger than the sum of its proper divisors (7376489259).

21112020021 is an equidigital number, since it uses as much as digits as its factorization.

21112020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84787315.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21112020021 its reverse (12002021112), we get a palindrome (33114041133).

The spelling of 21112020021 in words is "twenty-one billion, one hundred twelve million, twenty thousand, twenty-one".