213557 has 2 divisors, whose sum is σ = 213558. Its totient is φ = 213556.

The previous prime is 213553. The next prime is 213589. The reversal of 213557 is 755312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198916 + 14641 = 446^2 + 121^2 .

It is a cyclic number.

It is not a de Polignac number, because 213557 - 2² = 213553 is a prime.

It is equal to p₁₉₀₉₄ and since 213557 and 19094 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106778 + 106779.

It is an arithmetic number, because the mean of its divisors is an integer number (106779).

2²¹³⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

213557 is a deficient number, since it is larger than the sum of its proper divisors (1).

213557 is an equidigital number, since it uses as much as digits as its factorization.

213557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1050, while the sum is 23.

The square root of 213557 is about 462.1222781905. The cubic root of 213557 is about 59.7729380951.

Adding to 213557 its reverse (755312), we get a palindrome (968869).

The spelling of 213557 in words is "two hundred thirteen thousand, five hundred fifty-seven".