20784427 has 4 divisors (see below), whose sum is σ = 21176640. Its totient is φ = 20392216.

The previous prime is 20784409. The next prime is 20784443. The reversal of 20784427 is 72448702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20784427 - 2¹¹ = 20782379 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20784392 and 20784401.

It is not an unprimeable number, because it can be changed into a prime (20724427) 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, 196027 + ... + 196132.

It is an arithmetic number, because the mean of its divisors is an integer number (5294160).

Almost surely, 2^20784427 is an apocalyptic number.

20784427 is a deficient number, since it is larger than the sum of its proper divisors (392213).

20784427 is an equidigital number, since it uses as much as digits as its factorization.

20784427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392212.

The product of its (nonzero) digits is 25088, while the sum is 34.

The square root of 20784427 is about 4558.9940776448. The cubic root of 20784427 is about 274.9451218318.

The spelling of 20784427 in words is "twenty million, seven hundred eighty-four thousand, four hundred twenty-seven".