57281209 has 2 divisors, whose sum is σ = 57281210. Its totient is φ = 57281208.

The previous prime is 57281171. The next prime is 57281227. The reversal of 57281209 is 90218275.

57281209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57229225 + 51984 = 7565^2 + 228^2 .

It is a cyclic number.

It is not a de Polignac number, because 57281209 - 2²³ = 48892601 is a prime.

It is a super-2 number, since 2×57281209² = 6562273809003362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (57281249) 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 as a sum of consecutive naturals, namely, 28640604 + 28640605.

It is an arithmetic number, because the mean of its divisors is an integer number (28640605).

Almost surely, 2^57281209 is an apocalyptic number.

It is an amenable number.

57281209 is a deficient number, since it is larger than the sum of its proper divisors (1).

57281209 is an equidigital number, since it uses as much as digits as its factorization.

57281209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 57281209 is about 7568.4350429927. The cubic root of 57281209 is about 385.4819600793.

The spelling of 57281209 in words is "fifty-seven million, two hundred eighty-one thousand, two hundred nine".