28205172 has 60 divisors (see below), whose sum is σ = 74237856. Its totient is φ = 9337680.

The previous prime is 28205147. The next prime is 28205173. The reversal of 28205172 is 27150282.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28205173) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 85047 + ... + 85377.

Almost surely, 2^28205172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28205172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37118928).

28205172 is an abundant number, since it is smaller than the sum of its proper divisors (46032684).

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

28205172 is a wasteful number, since it uses less digits than its factorization.

28205172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610 (or 599 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 28205172 is about 5310.8541685872. The cubic root of 28205172 is about 304.3987870074.

The spelling of 28205172 in words is "twenty-eight million, two hundred five thousand, one hundred seventy-two".