20404321 has 8 divisors (see below), whose sum is σ = 23373504. Its totient is φ = 17448720.

The previous prime is 20404261. The next prime is 20404331. The reversal of 20404321 is 12340402.

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 20404321 - 2¹⁹ = 19880033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20404295 and 20404304.

It is not an unprimeable number, because it can be changed into a prime (20404331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66 + ... + 6388.

It is an arithmetic number, because the mean of its divisors is an integer number (2921688).

Almost surely, 2^20404321 is an apocalyptic number.

It is an amenable number.

20404321 is a deficient number, since it is larger than the sum of its proper divisors (2969183).

20404321 is an equidigital number, since it uses as much as digits as its factorization.

20404321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6791.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 20404321 is about 4517.1142336673. The cubic root of 20404321 is about 273.2587322022.

Adding to 20404321 its reverse (12340402), we get a palindrome (32744723).

The spelling of 20404321 in words is "twenty million, four hundred four thousand, three hundred twenty-one".