20784320 has 28 divisors (see below), whose sum is σ = 49493424. Its totient is φ = 8313600.

The previous prime is 20784317. The next prime is 20784331. The reversal of 20784320 is 2348702.

It is a self number, because there is not a number n which added to its sum of digits gives 20784320.

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, 32156 + ... + 32795.

Almost surely, 2^20784320 is an apocalyptic number.

20784320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20784320 is an abundant number, since it is smaller than the sum of its proper divisors (28709104).

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

20784320 is an equidigital number, since it uses as much as digits as its factorization.

20784320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64968 (or 64958 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 20784320 is about 4558.9823425848. The cubic root of 20784320 is about 274.9446500173.

The spelling of 20784320 in words is "twenty million, seven hundred eighty-four thousand, three hundred twenty".