213712 has 30 divisors (see below), whose sum is σ = 448818. Its totient is φ = 98496.

The previous prime is 213659. The next prime is 213713. The reversal of 213712 is 217312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 207936 + 5776 = 456^2 + 76^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213713) by changing a digit.

213712 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 5 ways as a sum of consecutive naturals, for example, 5758 + ... + 5794.

2²¹³⁷¹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224409).

213712 is an abundant number, since it is smaller than the sum of its proper divisors (235106).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213712 is a wasteful number, since it uses less digits than its factorization.

213712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83 (or 58 counting only the distinct ones).

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

The square root of 213712 is about 462.2899523027. The cubic root of 213712 is about 59.7873956948.

Subtracting 213712 from its reverse (217312), we obtain a square (3600 = 60²).

The spelling of 213712 in words is "two hundred thirteen thousand, seven hundred twelve".