28321169 has 4 divisors (see below), whose sum is σ = 29086644. Its totient is φ = 27555696.

The previous prime is 28321159. The next prime is 28321171. The reversal of 28321169 is 96112382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96112382 = 2 ⋅48056191.

It can be written as a sum of positive squares in 2 ways, for example, as 24880144 + 3441025 = 4988^2 + 1855^2 .

It is a cyclic number.

It is not a de Polignac number, because 28321169 - 2²⁰ = 27272593 is a prime.

It is a super-2 number, since 2×28321169² = 1604177227053122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28321109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 382682 + ... + 382755.

It is an arithmetic number, because the mean of its divisors is an integer number (7271661).

Almost surely, 2^28321169 is an apocalyptic number.

It is an amenable number.

28321169 is a deficient number, since it is larger than the sum of its proper divisors (765475).

28321169 is an equidigital number, since it uses as much as digits as its factorization.

28321169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765474.

The product of its digits is 5184, while the sum is 32.

The square root of 28321169 is about 5321.7637114025. The cubic root of 28321169 is about 304.8155078818.

The spelling of 28321169 in words is "twenty-eight million, three hundred twenty-one thousand, one hundred sixty-nine".