20021022020021 has 12 divisors (see below), whose sum is σ = 22008241686732. Its totient is φ = 18199553064000.

The previous prime is 20021022020017. The next prime is 20021022020023. The reversal of 20021022020021 is 12002022012002.

It can be written as a sum of positive squares in 2 ways, for example, as 19994410623121 + 26611396900 = 4471511^2 + 163130^2 .

It is not a de Polignac number, because 20021022020021 - 2² = 20021022020017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20021022019978 and 20021022020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021022020023) 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 11 ways as a sum of consecutive naturals, for example, 4645970 + ... + 7850291.

It is an arithmetic number, because the mean of its divisors is an integer number (1834020140561).

Almost surely, 2^{20021022020021} is an apocalyptic number.

It is an amenable number.

20021022020021 is a deficient number, since it is larger than the sum of its proper divisors (1987219666711).

20021022020021 is a wasteful number, since it uses less digits than its factorization.

20021022020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12509524 (or 12509513 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 20021022020021 its reverse (12002022012002), we get a palindrome (32023044032023).

The spelling of 20021022020021 in words is "twenty trillion, twenty-one billion, twenty-two million, twenty thousand, twenty-one".