28507400 has 24 divisors (see below), whose sum is σ = 66280170. Its totient is φ = 11402880.

The previous prime is 28507393. The next prime is 28507403. The reversal of 28507400 is 470582.

It can be written as a sum of positive squares in 3 ways, for example, as 21141604 + 7365796 = 4598^2 + 2714^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28507400.

It is not an unprimeable number, because it can be changed into a prime (28507403) by changing a digit.

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, 71069 + ... + 71468.

Almost surely, 2^28507400 is an apocalyptic number.

28507400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28507400 is an abundant number, since it is smaller than the sum of its proper divisors (37772770).

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

28507400 is a wasteful number, since it uses less digits than its factorization.

28507400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142553 (or 142544 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 28507400 is about 5339.2321545331. The cubic root of 28507400 is about 305.4821720314.

Adding to 28507400 its reverse (470582), we get a palindrome (28977982).

The spelling of 28507400 in words is "twenty-eight million, five hundred seven thousand, four hundred".