20002020021 has 12 divisors (see below), whose sum is σ = 30591324972. Its totient is φ = 12550286976.

The previous prime is 20002020013. The next prime is 20002020029. The reversal of 20002020021 is 12002020002.

It is an interprime number because it is at equal distance from previous prime (20002020013) and next prime (20002020029).

It can be written as a sum of positive squares in 2 ways, for example, as 15808032900 + 4193987121 = 125730^2 + 64761^2 .

It is not a de Polignac number, because 20002020021 - 2³ = 20002020013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20002019985 and 20002020012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20002020029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65365926 + ... + 65366231.

It is an arithmetic number, because the mean of its divisors is an integer number (2549277081).

Almost surely, 2^20002020021 is an apocalyptic number.

It is an amenable number.

20002020021 is a deficient number, since it is larger than the sum of its proper divisors (10589304951).

20002020021 is a wasteful number, since it uses less digits than its factorization.

20002020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130732180 (or 130732177 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

Adding to 20002020021 its reverse (12002020002), we get a palindrome (32004040023).

The spelling of 20002020021 in words is "twenty billion, two million, twenty thousand, twenty-one".