20001684 has 12 divisors (see below), whose sum is σ = 46670624. Its totient is φ = 6667224.

The previous prime is 20001679. The next prime is 20001703. The reversal of 20001684 is 48610002.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 20001684.

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 3 ways as a sum of consecutive naturals, for example, 833392 + ... + 833415.

Almost surely, 2^20001684 is an apocalyptic number.

It is an amenable number.

20001684 is an abundant number, since it is smaller than the sum of its proper divisors (26668940).

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

20001684 is a wasteful number, since it uses less digits than its factorization.

20001684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666814 (or 1666812 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 20001684 is about 4472.3242279602. The cubic root of 20001684 is about 271.4493799111.

Adding to 20001684 its reverse (48610002), we get a palindrome (68611686).

The spelling of 20001684 in words is "twenty million, one thousand, six hundred eighty-four".