28308940 has 24 divisors (see below), whose sum is σ = 64853712. Its totient is φ = 10294080.

The previous prime is 28308937. The next prime is 28308947. The reversal of 28308940 is 4980382.

It is a junction number, because it is equal to n+sod(n) for n = 28308896 and 28308905.

It is not an unprimeable number, because it can be changed into a prime (28308947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64119 + ... + 64558.

It is an arithmetic number, because the mean of its divisors is an integer number (2702238).

Almost surely, 2^28308940 is an apocalyptic number.

28308940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28308940 is an abundant number, since it is smaller than the sum of its proper divisors (36544772).

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

28308940 is a wasteful number, since it uses less digits than its factorization.

28308940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128697 (or 128695 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28308940 is about 5320.6146261499. The cubic root of 28308940 is about 304.7716287432.

The spelling of 28308940 in words is "twenty-eight million, three hundred eight thousand, nine hundred forty".