20785778 has 8 divisors (see below), whose sum is σ = 33577068. Its totient is φ = 9593424.

The previous prime is 20785763. The next prime is 20785819. The reversal of 20785778 is 87758702.

It can be written as a sum of positive squares in 2 ways, for example, as 20367169 + 418609 = 4513^2 + 647^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 399701 + ... + 399752.

Almost surely, 2^20785778 is an apocalyptic number.

20785778 is a deficient number, since it is larger than the sum of its proper divisors (12791290).

20785778 is a wasteful number, since it uses less digits than its factorization.

20785778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799468.

The product of its (nonzero) digits is 219520, while the sum is 44.

The square root of 20785778 is about 4559.1422438875. The cubic root of 20785778 is about 274.9510789010.

The spelling of 20785778 in words is "twenty million, seven hundred eighty-five thousand, seven hundred seventy-eight".