28173009 has 8 divisors (see below), whose sum is σ = 37604512. Its totient is φ = 18761760.

The previous prime is 28173001. The next prime is 28173011. The reversal of 28173009 is 90037182.

It is a happy number.

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

It is not a de Polignac number, because 28173009 - 2³ = 28173001 is a prime.

It is a super-2 number, since 2×28173009² = 1587436872228162, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28173001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1447 + ... + 7644.

It is an arithmetic number, because the mean of its divisors is an integer number (4700564).

Almost surely, 2^28173009 is an apocalyptic number.

It is an amenable number.

28173009 is a deficient number, since it is larger than the sum of its proper divisors (9431503).

28173009 is a wasteful number, since it uses less digits than its factorization.

28173009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10127.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 28173009 is about 5307.8252608766. The cubic root of 28173009 is about 304.2830387097.

The spelling of 28173009 in words is "twenty-eight million, one hundred seventy-three thousand, nine".