20847028 has 18 divisors (see below), whose sum is σ = 38506146. Its totient is φ = 9874224.

The previous prime is 20847017. The next prime is 20847053. The reversal of 20847028 is 82074802.

It can be written as a sum of positive squares in only one way, i.e., 17791524 + 3055504 = 4218^2 + 1748^2 .

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

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, 5775 + ... + 8662.

Almost surely, 2^20847028 is an apocalyptic number.

20847028 is the 2888-th heptagonal number.

It is an amenable number.

20847028 is a deficient number, since it is larger than the sum of its proper divisors (17659118).

20847028 is a wasteful number, since it uses less digits than its factorization.

20847028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14479 (or 14458 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 20847028 is about 4565.8545749947. The cubic root of 20847028 is about 275.2208825926.

The spelling of 20847028 in words is "twenty million, eight hundred forty-seven thousand, twenty-eight".