557021 has 2 divisors, whose sum is σ = 557022. Its totient is φ = 557020.

The previous prime is 557017. The next prime is 557027. The reversal of 557021 is 120755.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 511225 + 45796 = 715^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 557021 - 2² = 557017 is a prime.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 556984 and 557002.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 557021.

It is not a weakly prime, because it can be changed into another prime (557027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 278510 + 278511.

It is an arithmetic number, because the mean of its divisors is an integer number (278511).

2⁵⁵⁷⁰²¹ is an apocalyptic number.

It is an amenable number.

557021 is a deficient number, since it is larger than the sum of its proper divisors (1).

557021 is an equidigital number, since it uses as much as digits as its factorization.

557021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 557021 is about 746.3383950997. The cubic root of 557021 is about 82.2792876179.

Adding to 557021 its reverse (120755), we get a palindrome (677776).

The spelling of 557021 in words is "five hundred fifty-seven thousand, twenty-one".