212749 has 4 divisors (see below), whose sum is σ = 217980. Its totient is φ = 207520.

The previous prime is 212701. The next prime is 212777. The reversal of 212749 is 947212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 79524 + 133225 = 282^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 212749 - 2¹³ = 204557 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2554 + ... + 2635.

It is an arithmetic number, because the mean of its divisors is an integer number (54495).

2²¹²⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

212749 is a deficient number, since it is larger than the sum of its proper divisors (5231).

212749 is an equidigital number, since it uses as much as digits as its factorization.

212749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5230.

The product of its digits is 1008, while the sum is 25.

The square root of 212749 is about 461.2472222139. The cubic root of 212749 is about 59.6974585231.

It can be divided in two parts, 212 and 749, that added together give a square (961 = 31²).

The spelling of 212749 in words is "two hundred twelve thousand, seven hundred forty-nine".