28158605 has 8 divisors (see below), whose sum is σ = 33850872. Its totient is φ = 22486528.

The previous prime is 28158587. The next prime is 28158617. The reversal of 28158605 is 50685182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 259081 + 27899524 = 509^2 + 5282^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28158605 - 2⁶ = 28158541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1784 + ... + 7713.

It is an arithmetic number, because the mean of its divisors is an integer number (4231359).

Almost surely, 2^28158605 is an apocalyptic number.

It is an amenable number.

28158605 is a deficient number, since it is larger than the sum of its proper divisors (5692267).

28158605 is an equidigital number, since it uses as much as digits as its factorization.

28158605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10095.

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 28158605 is about 5306.4682228390. The cubic root of 28158605 is about 304.2311729913.

The spelling of 28158605 in words is "twenty-eight million, one hundred fifty-eight thousand, six hundred five".