28810640209 has 6 divisors (see below), whose sum is σ = 31197320646. Its totient is φ = 26594436960.

The previous prime is 28810640171. The next prime is 28810640239. The reversal of 28810640209 is 90204601882.

It can be written as a sum of positive squares in 3 ways, for example, as 1178892225 + 27631747984 = 34335^2 + 166228^2 .

It is not a de Polignac number, because 28810640209 - 2¹¹ = 28810638161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28810640239) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 85238412 + ... + 85238749.

It is an arithmetic number, because the mean of its divisors is an integer number (5199553441).

Almost surely, 2^28810640209 is an apocalyptic number.

It is an amenable number.

28810640209 is a deficient number, since it is larger than the sum of its proper divisors (2386680437).

28810640209 is a wasteful number, since it uses less digits than its factorization.

28810640209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170477187 (or 170477174 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 28810640209 in words is "twenty-eight billion, eight hundred ten million, six hundred forty thousand, two hundred nine".