213172 has 12 divisors (see below), whose sum is σ = 376740. Its totient is φ = 105536.

The previous prime is 213149. The next prime is 213173. The reversal of 213172 is 271312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 86436 + 126736 = 294^2 + 356^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213173) by changing a digit.

213172 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 354 + ... + 742.

It is an arithmetic number, because the mean of its divisors is an integer number (31395).

2²¹³¹⁷² is an apocalyptic number.

It is an amenable number.

213172 is a deficient number, since it is larger than the sum of its proper divisors (163568).

213172 is a wasteful number, since it uses less digits than its factorization.

213172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 528 counting only the distinct ones).

The product of its digits is 84, while the sum is 16.

The square root of 213172 is about 461.7055338633. The cubic root of 213172 is about 59.7369969895.

Adding to 213172 its reverse (271312), we get a palindrome (484484).

The spelling of 213172 in words is "two hundred thirteen thousand, one hundred seventy-two".