28172307 has 8 divisors (see below), whose sum is σ = 39540160. Its totient is φ = 17793000.

The previous prime is 28172299. The next prime is 28172341. The reversal of 28172307 is 70327182.

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

It is not a de Polignac number, because 28172307 - 2³ = 28172299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28172357) 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, 247069 + ... + 247182.

It is an arithmetic number, because the mean of its divisors is an integer number (4942520).

Almost surely, 2^28172307 is an apocalyptic number.

28172307 is a deficient number, since it is larger than the sum of its proper divisors (11367853).

28172307 is a wasteful number, since it uses less digits than its factorization.

28172307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494273.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 28172307 is about 5307.7591316864. The cubic root of 28172307 is about 304.2805113679.

Adding to 28172307 its reverse (70327182), we get a palindrome (98499489).

The spelling of 28172307 in words is "twenty-eight million, one hundred seventy-two thousand, three hundred seven".