28431072 has 72 divisors (see below), whose sum is σ = 85621536. Its totient is φ = 8918016.

The previous prime is 28431071. The next prime is 28431079. The reversal of 28431072 is 27013482.

28431072 is a `hidden beast` number, since 284 + 310 + 72 = 666.

28431072 is nontrivially palindromic in base 5.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28431071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1993 + ... + 7799.

It is an arithmetic number, because the mean of its divisors is an integer number (1189188).

Almost surely, 2^28431072 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 28431072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42810768).

28431072 is an abundant number, since it is smaller than the sum of its proper divisors (57190464).

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

28431072 is a wasteful number, since it uses less digits than its factorization.

28431072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5840 (or 5829 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 28431072 is about 5332.0795192870. The cubic root of 28431072 is about 305.2092875130.

The spelling of 28431072 in words is "twenty-eight million, four hundred thirty-one thousand, seventy-two".