20424321 has 12 divisors (see below), whose sum is σ = 29795220. Its totient is φ = 13480800.

The previous prime is 20424307. The next prime is 20424329. The reversal of 20424321 is 12342402.

It can be written as a sum of positive squares in 2 ways, for example, as 17943696 + 2480625 = 4236^2 + 1575^2 .

It is not a de Polignac number, because 20424321 - 2⁷ = 20424193 is a prime.

It is a super-2 number, since 2×20424321² = 834305776622082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20424294 and 20424303.

It is not an unprimeable number, because it can be changed into a prime (20424329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10326 + ... + 12143.

It is an arithmetic number, because the mean of its divisors is an integer number (2482935).

Almost surely, 2^20424321 is an apocalyptic number.

It is an amenable number.

20424321 is a deficient number, since it is larger than the sum of its proper divisors (9370899).

20424321 is a wasteful number, since it uses less digits than its factorization.

20424321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22576 (or 22573 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 20424321 is about 4519.3274942186. The cubic root of 20424321 is about 273.3479843756.

Adding to 20424321 its reverse (12342402), we get a palindrome (32766723).

The spelling of 20424321 in words is "twenty million, four hundred twenty-four thousand, three hundred twenty-one".