28688420 has 12 divisors (see below), whose sum is σ = 60245724. Its totient is φ = 11475360.

The previous prime is 28688419. The next prime is 28688447. The reversal of 28688420 is 2488682.

It can be written as a sum of positive squares in 2 ways, for example, as 11115556 + 17572864 = 3334^2 + 4192^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 717191 + ... + 717230.

It is an arithmetic number, because the mean of its divisors is an integer number (5020477).

Almost surely, 2^28688420 is an apocalyptic number.

28688420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28688420 is an abundant number, since it is smaller than the sum of its proper divisors (31557304).

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

28688420 is a wasteful number, since it uses less digits than its factorization.

28688420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434430 (or 1434428 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 28688420 is about 5356.1572045637. The cubic root of 28688420 is about 306.1274050469.

The spelling of 28688420 in words is "twenty-eight million, six hundred eighty-eight thousand, four hundred twenty".