20799840 has 96 divisors (see below), whose sum is σ = 69400800. Its totient is φ = 5218304.

The previous prime is 20799829. The next prime is 20799847. The reversal of 20799840 is 4899702.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20799847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6886 + ... + 9434.

It is an arithmetic number, because the mean of its divisors is an integer number (722925).

Almost surely, 2^20799840 is an apocalyptic number.

20799840 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 20799840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34700400).

20799840 is an abundant number, since it is smaller than the sum of its proper divisors (48600960).

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

20799840 is a wasteful number, since it uses less digits than its factorization.

20799840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2584 (or 2576 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 20799840 is about 4560.6841592024. The cubic root of 20799840 is about 275.0130682495.

The spelling of 20799840 in words is "twenty million, seven hundred ninety-nine thousand, eight hundred forty".