20817028 has 6 divisors (see below), whose sum is σ = 36429806. Its totient is φ = 10408512.

The previous prime is 20816953. The next prime is 20817037. The reversal of 20817028 is 82071802.

It can be written as a sum of positive squares in only one way, i.e., 20811844 + 5184 = 4562^2 + 72^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20816987 and 20817005.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2602125 + ... + 2602132.

Almost surely, 2^20817028 is an apocalyptic number.

It is an amenable number.

20817028 is a deficient number, since it is larger than the sum of its proper divisors (15612778).

20817028 is a wasteful number, since it uses less digits than its factorization.

20817028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5204261 (or 5204259 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 20817028 is about 4562.5681364775. The cubic root of 20817028 is about 275.0887999727.

The spelling of 20817028 in words is "twenty million, eight hundred seventeen thousand, twenty-eight".