212681 has 8 divisors (see below), whose sum is σ = 253824. Its totient is φ = 174240.

The previous prime is 212677. The next prime is 212683. The reversal of 212681 is 186212.

212681 = T₂₄₃ + T₂₄₄ + ... + T₂₄₉.

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

It is a cyclic number.

It is not a de Polignac number, because 212681 - 2² = 212677 is a prime.

It is a super-2 number, since 2×212681² = 90466415522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212683) 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 7 ways as a sum of consecutive naturals, for example, 500 + ... + 821.

It is an arithmetic number, because the mean of its divisors is an integer number (31728).

2²¹²⁶⁸¹ is an apocalyptic number.

It is an amenable number.

212681 is a deficient number, since it is larger than the sum of its proper divisors (41143).

212681 is a wasteful number, since it uses less digits than its factorization.

212681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1351.

The product of its digits is 192, while the sum is 20.

The square root of 212681 is about 461.1735031417. The cubic root of 212681 is about 59.6910975692.

Adding to 212681 its reverse (186212), we get a palindrome (398893).

The spelling of 212681 in words is "two hundred twelve thousand, six hundred eighty-one".