213315581 has 2 divisors, whose sum is σ = 213315582. Its totient is φ = 213315580.

The previous prime is 213315577. The next prime is 213315587. The reversal of 213315581 is 185513312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142587481 + 70728100 = 11941^2 + 8410^2 .

It is a cyclic number.

It is not a de Polignac number, because 213315581 - 2² = 213315577 is a prime.

It is a super-2 number, since 2×213315581² = 91007074194735122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213315587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106657790 + 106657791.

It is an arithmetic number, because the mean of its divisors is an integer number (106657791).

Almost surely, 2^213315581 is an apocalyptic number.

It is an amenable number.

213315581 is a deficient number, since it is larger than the sum of its proper divisors (1).

213315581 is an equidigital number, since it uses as much as digits as its factorization.

213315581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 29.

The square root of 213315581 is about 14605.3271445730. The cubic root of 213315581 is about 597.5040583748.

Adding to 213315581 its reverse (185513312), we get a palindrome (398828893).

The spelling of 213315581 in words is "two hundred thirteen million, three hundred fifteen thousand, five hundred eighty-one".