28128280 has 32 divisors (see below), whose sum is σ = 63721440. Its totient is φ = 11174400.

The previous prime is 28128271. The next prime is 28128307. The reversal of 28128280 is 8282182.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3712 + ... + 8368.

It is an arithmetic number, because the mean of its divisors is an integer number (1991295).

Almost surely, 2^28128280 is an apocalyptic number.

28128280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28128280 is an abundant number, since it is smaller than the sum of its proper divisors (35593160).

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

28128280 is a wasteful number, since it uses less digits than its factorization.

28128280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4819 (or 4815 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 31.

The square root of 28128280 is about 5303.6100912492. The cubic root of 28128280 is about 304.1219213177.

It can be divided in two parts, 281 and 28280, that added together give a 4-th power (28561 = 13⁴).

The spelling of 28128280 in words is "twenty-eight million, one hundred twenty-eight thousand, two hundred eighty".