213232121 has 4 divisors (see below), whose sum is σ = 213836532. Its totient is φ = 212627712.

The previous prime is 213232067. The next prime is 213232127. The reversal of 213232121 is 121232312.

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 106399225 + 106832896 = 10315^2 + 10336^2 .

It is a cyclic number.

It is not a de Polignac number, because 213232121 - 2¹⁰ = 213231097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 213232121.

It is not an unprimeable number, because it can be changed into a prime (213232127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301676 + ... + 302381.

It is an arithmetic number, because the mean of its divisors is an integer number (53459133).

Almost surely, 2^213232121 is an apocalyptic number.

It is an amenable number.

213232121 is a deficient number, since it is larger than the sum of its proper divisors (604411).

213232121 is an equidigital number, since it uses as much as digits as its factorization.

213232121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604410.

The product of its digits is 144, while the sum is 17.

The square root of 213232121 is about 14602.4696883781. The cubic root of 213232121 is about 597.4261234618.

Adding to 213232121 its reverse (121232312), we get a palindrome (334464433).

The spelling of 213232121 in words is "two hundred thirteen million, two hundred thirty-two thousand, one hundred twenty-one".