57280021 has 8 divisors (see below), whose sum is σ = 60913944. Its totient is φ = 53675520.

The previous prime is 57280007. The next prime is 57280061. The reversal of 57280021 is 12008275.

It can be written as a sum of positive squares in 4 ways, for example, as 579121 + 56700900 = 761^2 + 7530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 57280021 - 2¹¹ = 57277973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57280001) 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 7 ways as a sum of consecutive naturals, for example, 3270 + ... + 11191.

It is an arithmetic number, because the mean of its divisors is an integer number (7614243).

Almost surely, 2^57280021 is an apocalyptic number.

It is an amenable number.

57280021 is a deficient number, since it is larger than the sum of its proper divisors (3633923).

57280021 is a wasteful number, since it uses less digits than its factorization.

57280021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14711.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 57280021 is about 7568.3565587253. The cubic root of 57280021 is about 385.4792951232.

Adding to 57280021 its reverse (12008275), we get a palindrome (69288296).

The spelling of 57280021 in words is "fifty-seven million, two hundred eighty thousand, twenty-one".