20424440 has 16 divisors (see below), whose sum is σ = 45955080. Its totient is φ = 8169760.

The previous prime is 20424431. The next prime is 20424491. The reversal of 20424440 is 4442402.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

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, 255266 + ... + 255345.

Almost surely, 2^20424440 is an apocalyptic number.

20424440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20424440 is an abundant number, since it is smaller than the sum of its proper divisors (25530640).

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

20424440 is a wasteful number, since it uses less digits than its factorization.

20424440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510622 (or 510618 counting only the distinct ones).

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

The square root of 20424440 is about 4519.3406598751. The cubic root of 20424440 is about 273.3485152516.

Adding to 20424440 its reverse (4442402), we get a palindrome (24866842).

The spelling of 20424440 in words is "twenty million, four hundred twenty-four thousand, four hundred forty".