28206551709 has 24 divisors (see below), whose sum is σ = 46583081792. Its totient is φ = 16111146240.

The previous prime is 28206551629. The next prime is 28206551713. The reversal of 28206551709 is 90715560282.

28206551709 is a `hidden beast` number, since 2 + 8 + 20 + 6 + 551 + 70 + 9 = 666.

It is not a de Polignac number, because 28206551709 - 2¹¹ = 28206549661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28206551309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54957 + ... + 243789.

Almost surely, 2^28206551709 is an apocalyptic number.

It is an amenable number.

28206551709 is a deficient number, since it is larger than the sum of its proper divisors (18376530083).

28206551709 is a wasteful number, since it uses less digits than its factorization.

28206551709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191217 (or 191214 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 28206551709 in words is "twenty-eight billion, two hundred six million, five hundred fifty-one thousand, seven hundred nine".