209057 has 4 divisors (see below), whose sum is σ = 220080. Its totient is φ = 198036.

The previous prime is 209039. The next prime is 209063. The reversal of 209057 is 750902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 750902 = 2 ⋅375451.

It is a cyclic number.

It is not a de Polignac number, because 209057 - 2⁶ = 208993 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209057.

It is not an unprimeable number, because it can be changed into a prime (209257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5483 + ... + 5520.

It is an arithmetic number, because the mean of its divisors is an integer number (55020).

2²⁰⁹⁰⁵⁷ is an apocalyptic number.

It is an amenable number.

209057 is a deficient number, since it is larger than the sum of its proper divisors (11023).

209057 is a wasteful number, since it uses less digits than its factorization.

209057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11022.

The product of its (nonzero) digits is 630, while the sum is 23.

The square root of 209057 is about 457.2275144827. The cubic root of 209057 is about 59.3501158883.

Adding to 209057 its reverse (750902), we get a palindrome (959959).

The spelling of 209057 in words is "two hundred nine thousand, fifty-seven".