28088217 has 12 divisors (see below), whose sum is σ = 41668900. Its totient is φ = 18219168.

The previous prime is 28088197. The next prime is 28088219. The reversal of 28088217 is 71288082.

It can be written as a sum of positive squares in 2 ways, for example, as 20602521 + 7485696 = 4539^2 + 2736^2 .

It is not a de Polignac number, because 28088217 - 2⁷ = 28088089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28088219) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41842 + ... + 42507.

Almost surely, 2^28088217 is an apocalyptic number.

It is an amenable number.

28088217 is a deficient number, since it is larger than the sum of its proper divisors (13580683).

28088217 is a wasteful number, since it uses less digits than its factorization.

28088217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84392 (or 84389 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 28088217 is about 5299.8317897835. The cubic root of 28088217 is about 303.9774661564.

It can be divided in two parts, 2808 and 8217, that added together give a square (11025 = 105²).

The spelling of 28088217 in words is "twenty-eight million, eighty-eight thousand, two hundred seventeen".