20784993 has 16 divisors (see below), whose sum is σ = 29282880. Its totient is φ = 13077504.

The previous prime is 20784923. The next prime is 20785007. The reversal of 20784993 is 39948702.

It is not a de Polignac number, because 20784993 - 2¹⁰ = 20783969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20784913) 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, 19605 + ... + 20637.

It is an arithmetic number, because the mean of its divisors is an integer number (1830180).

Almost surely, 2^20784993 is an apocalyptic number.

It is an amenable number.

20784993 is a deficient number, since it is larger than the sum of its proper divisors (8497887).

20784993 is a wasteful number, since it uses less digits than its factorization.

20784993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 20784993 is about 4559.0561523192. The cubic root of 20784993 is about 274.9476175710.

The spelling of 20784993 in words is "twenty million, seven hundred eighty-four thousand, nine hundred ninety-three".