28178117 has 6 divisors (see below), whose sum is σ = 30972774. Its totient is φ = 25616360.

The previous prime is 28178113. The next prime is 28178119. The reversal of 28178117 is 71187182.

It can be written as a sum of positive squares in only one way, i.e., 22791076 + 5387041 = 4774^2 + 2321^2 .

It is not a de Polignac number, because 28178117 - 2² = 28178113 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 (28178113) 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, 116318 + ... + 116559.

It is an arithmetic number, because the mean of its divisors is an integer number (5162129).

Almost surely, 2^28178117 is an apocalyptic number.

It is an amenable number.

28178117 is a deficient number, since it is larger than the sum of its proper divisors (2794657).

28178117 is a wasteful number, since it uses less digits than its factorization.

28178117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232899 (or 232888 counting only the distinct ones).

The product of its digits is 6272, while the sum is 35.

The square root of 28178117 is about 5308.3064154210. The cubic root of 28178117 is about 304.3014272772.

The spelling of 28178117 in words is "twenty-eight million, one hundred seventy-eight thousand, one hundred seventeen".