20808428 has 12 divisors (see below), whose sum is σ = 37670640. Its totient is φ = 10045392.

The previous prime is 20808421. The next prime is 20808449. The reversal of 20808428 is 82480802.

It is a junction number, because it is equal to n+sod(n) for n = 20808394 and 20808403.

It is not an unprimeable number, because it can be changed into a prime (20808421) 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 3 ways as a sum of consecutive naturals, for example, 89576 + ... + 89807.

It is an arithmetic number, because the mean of its divisors is an integer number (3139220).

Almost surely, 2^20808428 is an apocalyptic number.

It is an amenable number.

20808428 is a deficient number, since it is larger than the sum of its proper divisors (16862212).

20808428 is a wasteful number, since it uses less digits than its factorization.

20808428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179416 (or 179414 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 32.

The square root of 20808428 is about 4561.6255874414. The cubic root of 20808428 is about 275.0509128876.

The spelling of 20808428 in words is "twenty million, eight hundred eight thousand, four hundred twenty-eight".