20778808 has 32 divisors (see below), whose sum is σ = 39836160. Its totient is φ = 10159200.

The previous prime is 20778803. The next prime is 20778833. The reversal of 20778808 is 80887702.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778803) 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 7 ways as a sum of consecutive naturals, for example, 124341 + ... + 124507.

It is an arithmetic number, because the mean of its divisors is an integer number (1244880).

Almost surely, 2^20778808 is an apocalyptic number.

It is an amenable number.

20778808 is a deficient number, since it is larger than the sum of its proper divisors (19057352).

20778808 is a wasteful number, since it uses less digits than its factorization.

20778808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 40.

The square root of 20778808 is about 4558.3777816236. The cubic root of 20778808 is about 274.9203427687.

The spelling of 20778808 in words is "twenty million, seven hundred seventy-eight thousand, eight hundred eight".