20683856 has 30 divisors (see below), whose sum is σ = 42307002. Its totient is φ = 9794880.

The previous prime is 20683853. The next prime is 20683879. The reversal of 20683856 is 65838602.

It can be written as a sum of positive squares in only one way, i.e., 20106256 + 577600 = 4484^2 + 760^2 .

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20683853) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3986 + ... + 7566.

Almost surely, 2^20683856 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 20683856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21153501).

20683856 is an abundant number, since it is smaller than the sum of its proper divisors (21623146).

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

20683856 is a wasteful number, since it uses less digits than its factorization.

20683856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3627 (or 3602 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 20683856 is about 4547.9507473147. The cubic root of 20683856 is about 274.5009394982.

The spelling of 20683856 in words is "twenty million, six hundred eighty-three thousand, eight hundred fifty-six".