20544021 has 12 divisors (see below), whose sum is σ = 29723148. Its totient is φ = 13673664.

The previous prime is 20544011. The next prime is 20544023. The reversal of 20544021 is 12044502.

20544021 is a `hidden beast` number, since 205 + 440 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8328996 + 12215025 = 2886^2 + 3495^2 .

It is not a de Polignac number, because 20544021 - 2¹⁰ = 20542997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20543985 and 20544003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20544023) 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 11 ways as a sum of consecutive naturals, for example, 5481 + ... + 8433.

It is an arithmetic number, because the mean of its divisors is an integer number (2476929).

Almost surely, 2^20544021 is an apocalyptic number.

It is an amenable number.

20544021 is a deficient number, since it is larger than the sum of its proper divisors (9179127).

20544021 is a wasteful number, since it uses less digits than its factorization.

20544021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3732 (or 3729 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 20544021 is about 4532.5512683256. The cubic root of 20544021 is about 273.8809444229.

Adding to 20544021 its reverse (12044502), we get a palindrome (32588523).

The spelling of 20544021 in words is "twenty million, five hundred forty-four thousand, twenty-one".