20016021 has 16 divisors (see below), whose sum is σ = 28382400. Its totient is φ = 12503808.

The previous prime is 20016019. The next prime is 20016043. The reversal of 20016021 is 12061002.

It is not a de Polignac number, because 20016021 - 2¹ = 20016019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20015988 and 20016006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20016121) 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 15 ways as a sum of consecutive naturals, for example, 12990 + ... + 14448.

It is an arithmetic number, because the mean of its divisors is an integer number (1773900).

Almost surely, 2^20016021 is an apocalyptic number.

It is an amenable number.

20016021 is a deficient number, since it is larger than the sum of its proper divisors (8366379).

20016021 is a wasteful number, since it uses less digits than its factorization.

20016021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 20016021 is about 4473.9267986859. The cubic root of 20016021 is about 271.5142217893.

Adding to 20016021 its reverse (12061002), we get a palindrome (32077023).

The spelling of 20016021 in words is "twenty million, sixteen thousand, twenty-one".