21022120021 has 8 divisors (see below), whose sum is σ = 24432488640. Its totient is φ = 17713553568.

The previous prime is 21022120019. The next prime is 21022120043. The reversal of 21022120021 is 12002122012.

It is a happy number.

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 21022120021 - 2¹ = 21022120019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21022119983 and 21022120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022120001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25450096 + ... + 25450921.

It is an arithmetic number, because the mean of its divisors is an integer number (3054061080).

Almost surely, 2^21022120021 is an apocalyptic number.

It is an amenable number.

21022120021 is a deficient number, since it is larger than the sum of its proper divisors (3410368619).

21022120021 is an equidigital number, since it uses as much as digits as its factorization.

21022120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50901083.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21022120021 its reverse (12002122012), we get a palindrome (33024242033).

The spelling of 21022120021 in words is "twenty-one billion, twenty-two million, one hundred twenty thousand, twenty-one".