28169904 has 160 divisors (see below), whose sum is σ = 89280000. Its totient is φ = 7639296.

The previous prime is 28169903. The next prime is 28169971. The reversal of 28169904 is 40996182.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28169903) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 477427 + ... + 477485.

It is an arithmetic number, because the mean of its divisors is an integer number (558000).

Almost surely, 2^28169904 is an apocalyptic number.

28169904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28169904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44640000).

28169904 is an abundant number, since it is smaller than the sum of its proper divisors (61110096).

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

28169904 is a wasteful number, since it uses less digits than its factorization.

28169904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 28169904 is about 5307.5327601438. The cubic root of 28169904 is about 304.2718597647.

It can be divided in two parts, 2816 and 9904, that added together give a triangular number (12720 = T₁₅₉).

The spelling of 28169904 in words is "twenty-eight million, one hundred sixty-nine thousand, nine hundred four".