20424400 has 30 divisors (see below), whose sum is σ = 49070582. Its totient is φ = 8169600.

The previous prime is 20424379. The next prime is 20424401. The reversal of 20424400 is 442402.

It can be written as a sum of positive squares in 3 ways, for example, as 138384 + 20286016 = 372^2 + 4504^2 .

It is a super-2 number, since 2×20424400² = 834312230720000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20424401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25131 + ... + 25930.

Almost surely, 2^20424400 is an apocalyptic number.

20424400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20424400 is an abundant number, since it is smaller than the sum of its proper divisors (28646182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20424400 is a wasteful number, since it uses less digits than its factorization.

20424400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51079 (or 51068 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 20424400 is about 4519.3362344486. The cubic root of 20424400 is about 273.3483368062.

Adding to 20424400 its reverse (442402), we get a palindrome (20866802).

The spelling of 20424400 in words is "twenty million, four hundred twenty-four thousand, four hundred".