20287856 has 20 divisors (see below), whose sum is σ = 39783912. Its totient is φ = 10021056.

The previous prime is 20287847. The next prime is 20287889. The reversal of 20287856 is 65878202.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 6311 + ... + 8966.

Almost surely, 2^20287856 is an apocalyptic number.

It is an amenable number.

20287856 is a deficient number, since it is larger than the sum of its proper divisors (19496056).

20287856 is a wasteful number, since it uses less digits than its factorization.

20287856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15368 (or 15362 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 20287856 is about 4504.2042582458. The cubic root of 20287856 is about 272.7378323723.

The spelling of 20287856 in words is "twenty million, two hundred eighty-seven thousand, eight hundred fifty-six".