20784480 has 192 divisors, whose sum is σ = 71850240. Its totient is φ = 5031936.

The previous prime is 20784451. The next prime is 20784493. The reversal of 20784480 is 8448702.

It is a Cunningham number, because it is equal to 4559²-1.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 392134 + ... + 392186.

It is an arithmetic number, because the mean of its divisors is an integer number (374220).

Almost surely, 2^20784480 is an apocalyptic number.

20784480 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 20784480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35925120).

20784480 is an abundant number, since it is smaller than the sum of its proper divisors (51065760).

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

20784480 is a wasteful number, since it uses less digits than its factorization.

20784480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 33.

The square root of 20784480 is about 4558.9998903268. Note that the first 3 decimals coincide. The cubic root of 20784480 is about 274.9453555337.

The spelling of 20784480 in words is "twenty million, seven hundred eighty-four thousand, four hundred eighty".