212109 has 8 divisors (see below), whose sum is σ = 299520. Its totient is φ = 133056.

The previous prime is 212099. The next prime is 212117. The reversal of 212109 is 901212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 212109 - 2⁹ = 211597 is a prime.

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

212109 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2029 + ... + 2130.

It is an arithmetic number, because the mean of its divisors is an integer number (37440).

2²¹²¹⁰⁹ is an apocalyptic number.

It is an amenable number.

212109 is a deficient number, since it is larger than the sum of its proper divisors (87411).

212109 is a wasteful number, since it uses less digits than its factorization.

212109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4179.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 212109 is about 460.5529285544. The cubic root of 212109 is about 59.6375369741.

The spelling of 212109 in words is "two hundred twelve thousand, one hundred nine".