20060021 has 4 divisors (see below), whose sum is σ = 20301792. Its totient is φ = 19818252.

The previous prime is 20060009. The next prime is 20060087. The reversal of 20060021 is 12006002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12006002 = 2 ⋅6003001.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20060021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20059984 and 20060011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20060321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120761 + ... + 120926.

It is an arithmetic number, because the mean of its divisors is an integer number (5075448).

Almost surely, 2^20060021 is an apocalyptic number.

It is an amenable number.

20060021 is a deficient number, since it is larger than the sum of its proper divisors (241771).

20060021 is an equidigital number, since it uses as much as digits as its factorization.

20060021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241770.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20060021 is about 4478.8414796686. The cubic root of 20060021 is about 271.7130272459.

Adding to 20060021 its reverse (12006002), we get a palindrome (32066023).

The spelling of 20060021 in words is "twenty million, sixty thousand, twenty-one".