213443121 has 32 divisors (see below), whose sum is σ = 301529088. Its totient is φ = 134136000.

The previous prime is 213443107. The next prime is 213443149. The reversal of 213443121 is 121344312.

It is not a de Polignac number, because 213443121 - 2⁷ = 213442993 is a prime.

It is a super-3 number, since 3×213443121³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (213443521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 850246 + ... + 850496.

It is an arithmetic number, because the mean of its divisors is an integer number (9422784).

Almost surely, 2^213443121 is an apocalyptic number.

It is an amenable number.

213443121 is a deficient number, since it is larger than the sum of its proper divisors (88085967).

213443121 is a wasteful number, since it uses less digits than its factorization.

213443121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501.

The product of its digits is 576, while the sum is 21.

The square root of 213443121 is about 14609.6927072406. The cubic root of 213443121 is about 597.6231159149.

Adding to 213443121 its reverse (121344312), we get a palindrome (334787433).

The spelling of 213443121 in words is "two hundred thirteen million, four hundred forty-three thousand, one hundred twenty-one".