20868688 has 30 divisors (see below), whose sum is σ = 42684954. Its totient is φ = 9882432.

The previous prime is 20868671. The next prime is 20868733. The reversal of 20868688 is 88686802.

It can be written as a sum of positive squares in only one way, i.e., 10679824 + 10188864 = 3268^2 + 3192^2 .

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 3970 + ... + 7582.

Almost surely, 2^20868688 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 20868688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21342477).

20868688 is an abundant number, since it is smaller than the sum of its proper divisors (21816266).

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

20868688 is a wasteful number, since it uses less digits than its factorization.

20868688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3659 (or 3634 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 46.

The square root of 20868688 is about 4568.2259138532. The cubic root of 20868688 is about 275.3161674924.

The spelling of 20868688 in words is "twenty million, eight hundred sixty-eight thousand, six hundred eighty-eight".