20006646 has 32 divisors (see below), whose sum is σ = 44074368. Its totient is φ = 6003840.

The previous prime is 20006641. The next prime is 20006663. The reversal of 20006646 is 64660002.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20006641) 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, 5646 + ... + 8478.

It is an arithmetic number, because the mean of its divisors is an integer number (1377324).

Almost surely, 2^20006646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20006646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22037184).

20006646 is an abundant number, since it is smaller than the sum of its proper divisors (24067722).

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

20006646 is a wasteful number, since it uses less digits than its factorization.

20006646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2956.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20006646 is about 4472.8789386703. The cubic root of 20006646 is about 271.4718250289.

Adding to 20006646 its reverse (64660002), we get a palindrome (84666648).

It can be divided in two parts, 2000 and 6646, that added together give a triangular number (8646 = T₁₃₁).

The spelling of 20006646 in words is "twenty million, six thousand, six hundred forty-six".