28129842 has 120 divisors (see below), whose sum is σ = 73577196. Its totient is φ = 7978176.

The previous prime is 28129841. The next prime is 28129853. The reversal of 28129842 is 24892182.

It can be written as a sum of positive squares in 2 ways, for example, as 28100601 + 29241 = 5301^2 + 171^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28129797 and 28129806.

It is not an unprimeable number, because it can be changed into a prime (28129841) 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 59 ways as a sum of consecutive naturals, for example, 760248 + ... + 760284.

Almost surely, 2^28129842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28129842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36788598).

28129842 is an abundant number, since it is smaller than the sum of its proper divisors (45447354).

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

28129842 is a wasteful number, since it uses less digits than its factorization.

28129842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 74 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 28129842 is about 5303.7573473906. The cubic root of 28129842 is about 304.1275506422.

The spelling of 28129842 in words is "twenty-eight million, one hundred twenty-nine thousand, eight hundred forty-two".