28009700 has 18 divisors (see below), whose sum is σ = 60781266. Its totient is φ = 11203840.

The previous prime is 28009669. The next prime is 28009721. The reversal of 28009700 is 790082.

It can be written as a sum of positive squares in 3 ways, for example, as 9278116 + 18731584 = 3046^2 + 4328^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28009700.

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 5 ways as a sum of consecutive naturals, for example, 139949 + ... + 140148.

It is an arithmetic number, because the mean of its divisors is an integer number (3376737).

Almost surely, 2^28009700 is an apocalyptic number.

28009700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28009700 is an abundant number, since it is smaller than the sum of its proper divisors (32771566).

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

28009700 is a wasteful number, since it uses less digits than its factorization.

28009700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280111 (or 280104 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 28009700 is about 5292.4191066090. The cubic root of 28009700 is about 303.6939585118.

Adding to 28009700 its reverse (790082), we get a palindrome (28799782).

The spelling of 28009700 in words is "twenty-eight million, nine thousand, seven hundred".