28390004 has 12 divisors (see below), whose sum is σ = 51842784. Its totient is φ = 13577784.

The previous prime is 28390003. The next prime is 28390091. The reversal of 28390004 is 40009382.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28390001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154202 + ... + 154385.

It is an arithmetic number, because the mean of its divisors is an integer number (4320232).

Almost surely, 2^28390004 is an apocalyptic number.

It is an amenable number.

28390004 is a deficient number, since it is larger than the sum of its proper divisors (23452780).

28390004 is a wasteful number, since it uses less digits than its factorization.

28390004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308614 (or 308612 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 28390004 is about 5328.2270972623. The cubic root of 28390004 is about 305.0622608719.

Adding to 28390004 its reverse (40009382), we get a palindrome (68399386).

The spelling of 28390004 in words is "twenty-eight million, three hundred ninety thousand, four".