28881428 has 12 divisors (see below), whose sum is σ = 51235380. Its totient is φ = 14242752.

The previous prime is 28881421. The next prime is 28881431. The reversal of 28881428 is 82418882.

It can be written as a sum of positive squares in 2 ways, for example, as 21548164 + 7333264 = 4642^2 + 2708^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28881421) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 49163 + ... + 49746.

It is an arithmetic number, because the mean of its divisors is an integer number (4269615).

Almost surely, 2^28881428 is an apocalyptic number.

It is an amenable number.

28881428 is a deficient number, since it is larger than the sum of its proper divisors (22353952).

28881428 is a wasteful number, since it uses less digits than its factorization.

28881428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98986 (or 98984 counting only the distinct ones).

The product of its digits is 65536, while the sum is 41.

The square root of 28881428 is about 5374.1443970180. The cubic root of 28881428 is about 306.8123855891.

The spelling of 28881428 in words is "twenty-eight million, eight hundred eighty-one thousand, four hundred twenty-eight".