28021005 has 16 divisors (see below), whose sum is σ = 49815360. Its totient is φ = 14944464.

The previous prime is 28021003. The next prime is 28021009. The reversal of 28021005 is 50012082.

It is not a de Polignac number, because 28021005 - 2¹ = 28021003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28021001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103647 + ... + 103916.

It is an arithmetic number, because the mean of its divisors is an integer number (3113460).

Almost surely, 2^28021005 is an apocalyptic number.

It is an amenable number.

28021005 is a deficient number, since it is larger than the sum of its proper divisors (21794355).

28021005 is a wasteful number, since it uses less digits than its factorization.

28021005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207577 (or 207571 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 28021005 is about 5293.4870359717. The cubic root of 28021005 is about 303.7348110070.

Adding to 28021005 its reverse (50012082), we get a palindrome (78033087).

The spelling of 28021005 in words is "twenty-eight million, twenty-one thousand, five".