57421728 has 216 divisors, whose sum is σ = 205218468. Its totient is φ = 15095808.

The previous prime is 57421717. The next prime is 57421729. The reversal of 57421728 is 82712475.

57421728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 41835024 + 15586704 = 6468^2 + 3948^2 .

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 = 57421692 and 57421701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57421729) 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 35 ways as a sum of consecutive naturals, for example, 183300 + ... + 183612.

Almost surely, 2^57421728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 57421728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102609234).

57421728 is an abundant number, since it is smaller than the sum of its proper divisors (147796740).

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

57421728 is a wasteful number, since it uses less digits than its factorization.

57421728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356 (or 338 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 57421728 is about 7577.7125836231. The cubic root of 57421728 is about 385.7969168059.

The spelling of 57421728 in words is "fifty-seven million, four hundred twenty-one thousand, seven hundred twenty-eight".