28308732 has 12 divisors (see below), whose sum is σ = 66053736. Its totient is φ = 9436240.

The previous prime is 28308713. The next prime is 28308733. The reversal of 28308732 is 23780382.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28308693 and 28308702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28308733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1179519 + ... + 1179542.

It is an arithmetic number, because the mean of its divisors is an integer number (5504478).

Almost surely, 2^28308732 is an apocalyptic number.

It is an amenable number.

28308732 is an abundant number, since it is smaller than the sum of its proper divisors (37745004).

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

28308732 is a wasteful number, since it uses less digits than its factorization.

28308732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2359068 (or 2359066 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 28308732 is about 5320.5950795000. The cubic root of 28308732 is about 304.7708823047.

The spelling of 28308732 in words is "twenty-eight million, three hundred eight thousand, seven hundred thirty-two".