20688884 has 6 divisors (see below), whose sum is σ = 36205554. Its totient is φ = 10344440.

The previous prime is 20688869. The next prime is 20688907. The reversal of 20688884 is 48888602.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 77284 = 4540^2 + 278^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2586107 + ... + 2586114.

It is an arithmetic number, because the mean of its divisors is an integer number (6034259).

Almost surely, 2^20688884 is an apocalyptic number.

It is an amenable number.

20688884 is a deficient number, since it is larger than the sum of its proper divisors (15516670).

20688884 is a wasteful number, since it uses less digits than its factorization.

20688884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5172225 (or 5172223 counting only the distinct ones).

The product of its (nonzero) digits is 196608, while the sum is 44.

The square root of 20688884 is about 4548.5034901603. The cubic root of 20688884 is about 274.5231803367.

The spelling of 20688884 in words is "twenty million, six hundred eighty-eight thousand, eight hundred eighty-four".