28820012 has 24 divisors (see below), whose sum is σ = 56678496. Its totient is φ = 12722688.

The previous prime is 28820009. The next prime is 28820023. The reversal of 28820012 is 21002882.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 28820012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10853 + ... + 13244.

It is an arithmetic number, because the mean of its divisors is an integer number (2361604).

Almost surely, 2^28820012 is an apocalyptic number.

It is an amenable number.

28820012 is a deficient number, since it is larger than the sum of its proper divisors (27858484).

28820012 is a wasteful number, since it uses less digits than its factorization.

28820012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24137 (or 24135 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 28820012 is about 5368.4273302337. The cubic root of 28820012 is about 306.5947536692.

Adding to 28820012 its reverse (21002882), we get a palindrome (49822894).

The spelling of 28820012 in words is "twenty-eight million, eight hundred twenty thousand, twelve".