28881684 has 60 divisors (see below), whose sum is σ = 81322164. Its totient is φ = 8885376.

The previous prime is 28881679. The next prime is 28881703. The reversal of 28881684 is 48618882.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1633284 + 27248400 = 1278^2 + 5220^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 784 + ... + 7640.

Almost surely, 2^28881684 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 28881684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40661082).

28881684 is an abundant number, since it is smaller than the sum of its proper divisors (52440480).

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

28881684 is a wasteful number, since it uses less digits than its factorization.

28881684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6886 (or 6875 counting only the distinct ones).

The product of its digits is 196608, while the sum is 45.

The square root of 28881684 is about 5374.1682147101. The cubic root of 28881684 is about 306.8132920972.

The spelling of 28881684 in words is "twenty-eight million, eight hundred eighty-one thousand, six hundred eighty-four".