28028172 has 24 divisors (see below), whose sum is σ = 69246576. Its totient is φ = 8793088.

The previous prime is 28028171. The next prime is 28028183. The reversal of 28028172 is 27182082.

It is a happy number.

It is a super-3 number, since 3×28028172³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (28028171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68493 + ... + 68900.

It is an arithmetic number, because the mean of its divisors is an integer number (2885274).

Almost surely, 2^28028172 is an apocalyptic number.

It is an amenable number.

28028172 is an abundant number, since it is smaller than the sum of its proper divisors (41218404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28028172 is a wasteful number, since it uses less digits than its factorization.

28028172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137417 (or 137415 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 28028172 is about 5294.1639566602. The cubic root of 28028172 is about 303.7607044611.

The spelling of 28028172 in words is "twenty-eight million, twenty-eight thousand, one hundred seventy-two".