28321120161 has 6 divisors (see below), whose sum is σ = 40908284690. Its totient is φ = 18880746768.

The previous prime is 28321120159. The next prime is 28321120171. The reversal of 28321120161 is 16102112382.

It can be written as a sum of positive squares in only one way, i.e., 22749990561 + 5571129600 = 150831^2 + 74640^2 .

It is not a de Polignac number, because 28321120161 - 2¹ = 28321120159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28321120171) 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, 1573395556 + ... + 1573395573.

Almost surely, 2^28321120161 is an apocalyptic number.

It is an amenable number.

28321120161 is a deficient number, since it is larger than the sum of its proper divisors (12587164529).

28321120161 is a wasteful number, since it uses less digits than its factorization.

28321120161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3146791135 (or 3146791132 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The spelling of 28321120161 in words is "twenty-eight billion, three hundred twenty-one million, one hundred twenty thousand, one hundred sixty-one".