20688066 has 24 divisors (see below), whose sum is σ = 51227904. Its totient is φ = 5910840.

The previous prime is 20688043. The next prime is 20688071. The reversal of 20688066 is 66088602.

It is a self number, because there is not a number n which added to its sum of digits gives 20688066.

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 11 ways as a sum of consecutive naturals, for example, 81970 + ... + 82221.

It is an arithmetic number, because the mean of its divisors is an integer number (2134496).

Almost surely, 2^20688066 is an apocalyptic number.

20688066 is an abundant number, since it is smaller than the sum of its proper divisors (30539838).

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

20688066 is a wasteful number, since it uses less digits than its factorization.

20688066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164206 (or 164203 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 20688066 is about 4548.4135695867. The cubic root of 20688066 is about 274.5195622437.

The spelling of 20688066 in words is "twenty million, six hundred eighty-eight thousand, sixty-six".