213181 has 2 divisors, whose sum is σ = 213182. Its totient is φ = 213180.

The previous prime is 213173. The next prime is 213193. The reversal of 213181 is 181312.

213181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210681 + 2500 = 459^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 213181 - 2³ = 213173 is a prime.

It is a super-2 number, since 2×213181² = 90892277522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106590 + 106591.

It is an arithmetic number, because the mean of its divisors is an integer number (106591).

2²¹³¹⁸¹ is an apocalyptic number.

It is an amenable number.

213181 is a deficient number, since it is larger than the sum of its proper divisors (1).

213181 is an equidigital number, since it uses as much as digits as its factorization.

213181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 16.

The square root of 213181 is about 461.7152802323. The cubic root of 213181 is about 59.7378376650.

Adding to 213181 its reverse (181312), we get a palindrome (394493).

It can be divided in two parts, 2 and 13181, that multiplied together give a palindrome (26362).

The spelling of 213181 in words is "two hundred thirteen thousand, one hundred eighty-one".