57281321 has 2 divisors, whose sum is σ = 57281322. Its totient is φ = 57281320.

The previous prime is 57281311. The next prime is 57281327. The reversal of 57281321 is 12318275.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52765696 + 4515625 = 7264^2 + 2125^2 .

It is a cyclic number.

It is not a de Polignac number, because 57281321 - 2¹⁰ = 57280297 is a prime.

It is a super-2 number, since 2×57281321² = 6562299471010082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (57281327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28640660 + 28640661.

It is an arithmetic number, because the mean of its divisors is an integer number (28640661).

Almost surely, 2^57281321 is an apocalyptic number.

It is an amenable number.

57281321 is a deficient number, since it is larger than the sum of its proper divisors (1).

57281321 is an equidigital number, since it uses as much as digits as its factorization.

57281321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 29.

The square root of 57281321 is about 7568.4424421409. The cubic root of 57281321 is about 385.4822113191.

Adding to 57281321 its reverse (12318275), we get a palindrome (69599596).

The spelling of 57281321 in words is "fifty-seven million, two hundred eighty-one thousand, three hundred twenty-one".