20020021 has 8 divisors (see below), whose sum is σ = 23094720. Its totient is φ = 16999008.

The previous prime is 20020019. The next prime is 20020027. The reversal of 20020021 is 12002002.

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 20020021 - 2¹ = 20020019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20019986 and 20020013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20020027) 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, 12616 + ... + 14113.

It is an arithmetic number, because the mean of its divisors is an integer number (2886840).

Almost surely, 2^20020021 is an apocalyptic number.

It is an amenable number.

20020021 is a deficient number, since it is larger than the sum of its proper divisors (3074699).

20020021 is a wasteful number, since it uses less digits than its factorization.

20020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26843.

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 20020021 is about 4474.3738109371. The cubic root of 20020021 is about 271.5323070446.

Adding to 20020021 its reverse (12002002), we get a palindrome (32022023).

The spelling of 20020021 in words is "twenty million, twenty thousand, twenty-one".