20838440 has 64 divisors (see below), whose sum is σ = 56419200. Its totient is φ = 6766848.

The previous prime is 20838439. The next prime is 20838449. The reversal of 20838440 is 4483802.

It is not an unprimeable number, because it can be changed into a prime (20838449) 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 15 ways as a sum of consecutive naturals, for example, 3362 + ... + 7278.

It is an arithmetic number, because the mean of its divisors is an integer number (881550).

Almost surely, 2^20838440 is an apocalyptic number.

20838440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20838440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28209600).

20838440 is an abundant number, since it is smaller than the sum of its proper divisors (35580760).

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

20838440 is a wasteful number, since it uses less digits than its factorization.

20838440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3954 (or 3950 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 20838440 is about 4564.9140189055. The cubic root of 20838440 is about 275.1830846936.

The spelling of 20838440 in words is "twenty million, eight hundred thirty-eight thousand, four hundred forty".