212135321 has 4 divisors (see below), whose sum is σ = 213683892. Its totient is φ = 210586752.

The previous prime is 212135293. The next prime is 212135347. The reversal of 212135321 is 123531212.

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 116877721 + 95257600 = 10811^2 + 9760^2 .

It is a cyclic number.

It is not a de Polignac number, because 212135321 - 2¹⁴ = 212118937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212135293 and 212135302.

It is not an unprimeable number, because it can be changed into a prime (212135221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 774080 + ... + 774353.

It is an arithmetic number, because the mean of its divisors is an integer number (53420973).

Almost surely, 2^212135321 is an apocalyptic number.

It is an amenable number.

212135321 is a deficient number, since it is larger than the sum of its proper divisors (1548571).

212135321 is a wasteful number, since it uses less digits than its factorization.

212135321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548570.

The product of its digits is 360, while the sum is 20.

The square root of 212135321 is about 14564.8659794727. The cubic root of 212135321 is about 596.4000371631.

Adding to 212135321 its reverse (123531212), we get a palindrome (335666533).

The spelling of 212135321 in words is "two hundred twelve million, one hundred thirty-five thousand, three hundred twenty-one".