28020004 has 12 divisors (see below), whose sum is σ = 50175664. Its totient is φ = 13684104.

The previous prime is 28019993. The next prime is 28020023. The reversal of 28020004 is 40002082.

It is a self number, because there is not a number n which added to its sum of digits gives 28020004.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81282 + ... + 81625.

Almost surely, 2^28020004 is an apocalyptic number.

It is an amenable number.

28020004 is a deficient number, since it is larger than the sum of its proper divisors (22155660).

28020004 is a wasteful number, since it uses less digits than its factorization.

28020004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162954 (or 162952 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 28020004 is about 5293.3924849760. The cubic root of 28020004 is about 303.7311941707.

Adding to 28020004 its reverse (40002082), we get a palindrome (68022086).

The spelling of 28020004 in words is "twenty-eight million, twenty thousand, four".