22021020021 has 48 divisors (see below), whose sum is σ = 39720958592. Its totient is φ = 10559514240.

The previous prime is 22021020017. The next prime is 22021020037. The reversal of 22021020021 is 12002012022.

It is not a de Polignac number, because 22021020021 - 2² = 22021020017 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 22021019979 and 22021020006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021020041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 300286 + ... + 366351.

Almost surely, 2^22021020021 is an apocalyptic number.

22021020021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22021020021 is a deficient number, since it is larger than the sum of its proper divisors (17699938571).

22021020021 is a wasteful number, since it uses less digits than its factorization.

22021020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666682 (or 666671 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 22021020021 its reverse (12002012022), we get a palindrome (34023032043).

The spelling of 22021020021 in words is "twenty-two billion, twenty-one million, twenty thousand, twenty-one".