20404424221 has 4 divisors (see below), whose sum is σ = 20405667744. Its totient is φ = 20403180700.

The previous prime is 20404424219. The next prime is 20404424231. The reversal of 20404424221 is 12242440402.

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: 12242440402 = 2 ⋅6121220201.

It is a cyclic number.

It is not a de Polignac number, because 20404424221 - 2¹ = 20404424219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20404424231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 596815 + ... + 630076.

It is an arithmetic number, because the mean of its divisors is an integer number (5101416936).

Almost surely, 2^20404424221 is an apocalyptic number.

It is an amenable number.

20404424221 is a deficient number, since it is larger than the sum of its proper divisors (1243523).

20404424221 is a wasteful number, since it uses less digits than its factorization.

20404424221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1243522.

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 20404424221 its reverse (12242440402), we get a palindrome (32646864623).

The spelling of 20404424221 in words is "twenty billion, four hundred four million, four hundred twenty-four thousand, two hundred twenty-one".