28391169 has 16 divisors (see below), whose sum is σ = 38747520. Its totient is φ = 18485760.

The previous prime is 28391141. The next prime is 28391179. The reversal of 28391169 is 96119382.

It is not a de Polignac number, because 28391169 - 2⁹ = 28390657 is a prime.

It is a super-2 number, since 2×28391169² = 1612116954373122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28391119) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 30097 + ... + 31025.

It is an arithmetic number, because the mean of its divisors is an integer number (2421720).

Almost surely, 2^28391169 is an apocalyptic number.

It is an amenable number.

28391169 is a deficient number, since it is larger than the sum of its proper divisors (10356351).

28391169 is a wasteful number, since it uses less digits than its factorization.

28391169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1160.

The product of its digits is 23328, while the sum is 39.

The square root of 28391169 is about 5328.3364195591. The cubic root of 28391169 is about 305.0664336161.

The spelling of 28391169 in words is "twenty-eight million, three hundred ninety-one thousand, one hundred sixty-nine".