20943280 has 20 divisors (see below), whose sum is σ = 48693312. Its totient is φ = 8377280.

The previous prime is 20943257. The next prime is 20943281. The reversal of 20943280 is 8234902.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (20943281) 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 3 ways as a sum of consecutive naturals, for example, 130816 + ... + 130975.

Almost surely, 2^20943280 is an apocalyptic number.

20943280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20943280 is an abundant number, since it is smaller than the sum of its proper divisors (27750032).

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

20943280 is a wasteful number, since it uses less digits than its factorization.

20943280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261804 (or 261798 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20943280 is about 4576.3828511172. The cubic root of 20943280 is about 275.6438029106.

The spelling of 20943280 in words is "twenty million, nine hundred forty-three thousand, two hundred eighty".