28149804 has 72 divisors (see below), whose sum is σ = 73801728. Its totient is φ = 9041760.

The previous prime is 28149761. The next prime is 28149809. The reversal of 28149804 is 40894182.

It is a super-2 number, since 2×28149804² = 1584822930476832, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28149809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214819 + ... + 214949.

It is an arithmetic number, because the mean of its divisors is an integer number (1025024).

Almost surely, 2^28149804 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 28149804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36900864).

28149804 is an abundant number, since it is smaller than the sum of its proper divisors (45651924).

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

28149804 is a wasteful number, since it uses less digits than its factorization.

28149804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315 (or 310 counting only the distinct ones).

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

The square root of 28149804 is about 5305.6388870710. The cubic root of 28149804 is about 304.1994737700.

The spelling of 28149804 in words is "twenty-eight million, one hundred forty-nine thousand, eight hundred four".