28690428 has 48 divisors (see below), whose sum is σ = 72436896. Its totient is φ = 8785920.

The previous prime is 28690423. The next prime is 28690439. The reversal of 28690428 is 82409682.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28690421) 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 15 ways as a sum of consecutive naturals, for example, 54808 + ... + 55328.

It is an arithmetic number, because the mean of its divisors is an integer number (1509102).

Almost surely, 2^28690428 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 28690428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36218448).

28690428 is an abundant number, since it is smaller than the sum of its proper divisors (43746468).

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

28690428 is a wasteful number, since it uses less digits than its factorization.

28690428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 28690428 is about 5356.3446491054. The cubic root of 28690428 is about 306.1345471794.

The spelling of 28690428 in words is "twenty-eight million, six hundred ninety thousand, four hundred twenty-eight".