20424004021 has 8 divisors (see below), whose sum is σ = 20722206680. Its totient is φ = 20126299392.

The previous prime is 20424003997. The next prime is 20424004043. The reversal of 20424004021 is 12040042402.

It can be written as a sum of positive squares in 4 ways, for example, as 285272100 + 20138731921 = 16890^2 + 141911^2 .

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 20424004021 - 2⁵ = 20424003989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20424004021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20424004061) 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 7 ways as a sum of consecutive naturals, for example, 41490 + ... + 206323.

It is an arithmetic number, because the mean of its divisors is an integer number (2590275835).

Almost surely, 2^20424004021 is an apocalyptic number.

It is an amenable number.

20424004021 is a deficient number, since it is larger than the sum of its proper divisors (298202659).

20424004021 is a wasteful number, since it uses less digits than its factorization.

20424004021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249015.

The product of its (nonzero) digits is 512, while the sum is 19.

Adding to 20424004021 its reverse (12040042402), we get a palindrome (32464046423).

The spelling of 20424004021 in words is "twenty billion, four hundred twenty-four million, four thousand, twenty-one".