20172424 has 16 divisors (see below), whose sum is σ = 37875420. Its totient is φ = 10072320.

The previous prime is 20172419. The next prime is 20172443. The reversal of 20172424 is 42427102.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 84100 = 4482^2 + 290^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20172395 and 20172404.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7044 + ... + 9484.

Almost surely, 2^20172424 is an apocalyptic number.

It is an amenable number.

20172424 is a deficient number, since it is larger than the sum of its proper divisors (17702996).

20172424 is a wasteful number, since it uses less digits than its factorization.

20172424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3480 (or 3476 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 20172424 is about 4491.3721734009. The cubic root of 20172424 is about 272.2195819140.

Adding to 20172424 its reverse (42427102), we get a palindrome (62599526).

The spelling of 20172424 in words is "twenty million, one hundred seventy-two thousand, four hundred twenty-four".