20847936 has 56 divisors (see below), whose sum is σ = 57570624. Its totient is φ = 6645760.

The previous prime is 20847923. The next prime is 20847941. The reversal of 20847936 is 63974802.

It is a junction number, because it is equal to n+sod(n) for n = 20847894 and 20847903.

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 7 ways as a sum of consecutive naturals, for example, 2056 + ... + 6776.

Almost surely, 2^20847936 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20847936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28785312).

20847936 is an abundant number, since it is smaller than the sum of its proper divisors (36722688).

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

20847936 is a wasteful number, since it uses less digits than its factorization.

20847936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4759 (or 4749 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 20847936 is about 4565.9540076527. The cubic root of 20847936 is about 275.2248783170.

The spelling of 20847936 in words is "twenty million, eight hundred forty-seven thousand, nine hundred thirty-six".