28001604 has 12 divisors (see below), whose sum is σ = 65337104. Its totient is φ = 9333864.

The previous prime is 28001593. The next prime is 28001609. The reversal of 28001604 is 40610082.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (28001609) 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 3 ways as a sum of consecutive naturals, for example, 1166722 + ... + 1166745.

Almost surely, 2^28001604 is an apocalyptic number.

It is an amenable number.

28001604 is an abundant number, since it is smaller than the sum of its proper divisors (37335500).

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

28001604 is a wasteful number, since it uses less digits than its factorization.

28001604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333474 (or 2333472 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 28001604 is about 5291.6541837123. The cubic root of 28001604 is about 303.6646955158.

Adding to 28001604 its reverse (40610082), we get a palindrome (68611686).

The spelling of 28001604 in words is "twenty-eight million, one thousand, six hundred four".