28057428 has 120 divisors (see below), whose sum is σ = 85377600. Its totient is φ = 7869312.

The previous prime is 28057411. The next prime is 28057439. The reversal of 28057428 is 82475082.

It is a happy number.

28057428 is a `hidden beast` number, since 2 + 80 + 574 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28057392 and 28057401.

It is a congruent number.

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 39 ways as a sum of consecutive naturals, for example, 201783 + ... + 201921.

It is an arithmetic number, because the mean of its divisors is an integer number (711480).

Almost surely, 2^28057428 is an apocalyptic number.

28057428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28057428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42688800).

28057428 is an abundant number, since it is smaller than the sum of its proper divisors (57320172).

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

28057428 is a wasteful number, since it uses less digits than its factorization.

28057428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 28057428 is about 5296.9262785129. The cubic root of 28057428 is about 303.8663568849.

The spelling of 28057428 in words is "twenty-eight million, fifty-seven thousand, four hundred twenty-eight".