21022212021 has 8 divisors (see below), whose sum is σ = 28037659104. Its totient is φ = 14010786480.

The previous prime is 21022212017. The next prime is 21022212023. The reversal of 21022212021 is 12021222012.

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

It is not a de Polignac number, because 21022212021 - 2² = 21022212017 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022212023) 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, 993166 + ... + 1014111.

It is an arithmetic number, because the mean of its divisors is an integer number (3504707388).

Almost surely, 2^21022212021 is an apocalyptic number.

It is an amenable number.

21022212021 is a deficient number, since it is larger than the sum of its proper divisors (7015447083).

21022212021 is a wasteful number, since it uses less digits than its factorization.

21022212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2010771.

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

Adding to 21022212021 its reverse (12021222012), we get a palindrome (33043434033).

Subtracting from 21022212021 its reverse (12021222012), we obtain a palindrome (9000990009).

The spelling of 21022212021 in words is "twenty-one billion, twenty-two million, two hundred twelve thousand, twenty-one".