20404424 has 16 divisors (see below), whose sum is σ = 38638620. Its totient is φ = 10100800.

The previous prime is 20404421. The next prime is 20404441. The reversal of 20404424 is 42440402.

It can be written as a sum of positive squares in 2 ways, for example, as 14303524 + 6100900 = 3782^2 + 2470^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20404396 and 20404405.

It is not an unprimeable number, because it can be changed into a prime (20404421) 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, 11819 + ... + 13434.

Almost surely, 2^20404424 is an apocalyptic number.

It is an amenable number.

20404424 is a deficient number, since it is larger than the sum of its proper divisors (18234196).

20404424 is a wasteful number, since it uses less digits than its factorization.

20404424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25360 (or 25356 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

The square root of 20404424 is about 4517.1256347372. The cubic root of 20404424 is about 273.2591920003.

Adding to 20404424 its reverse (42440402), we get a palindrome (62844826).

The spelling of 20404424 in words is "twenty million, four hundred four thousand, four hundred twenty-four".