20778028 has 6 divisors (see below), whose sum is σ = 36361556. Its totient is φ = 10389012.

The previous prime is 20778019. The next prime is 20778071. The reversal of 20778028 is 82087702.

It is a junction number, because it is equal to n+sod(n) for n = 20777984 and 20778002.

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, 2597250 + ... + 2597257.

Almost surely, 2^20778028 is an apocalyptic number.

It is an amenable number.

20778028 is a deficient number, since it is larger than the sum of its proper divisors (15583528).

20778028 is a wasteful number, since it uses less digits than its factorization.

20778028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5194511 (or 5194509 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 34.

The square root of 20778028 is about 4558.2922240681. The cubic root of 20778028 is about 274.9169027166.

The spelling of 20778028 in words is "twenty million, seven hundred seventy-eight thousand, twenty-eight".