213435521 has 4 divisors (see below), whose sum is σ = 229853652. Its totient is φ = 197017392.

The previous prime is 213435511. The next prime is 213435539. The reversal of 213435521 is 125534312.

It is a happy number.

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 140161921 + 73273600 = 11839^2 + 8560^2 .

It is not a de Polignac number, because 213435521 - 2¹⁴ = 213419137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213435511) 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 3 ways as a sum of consecutive naturals, for example, 8209046 + ... + 8209071.

It is an arithmetic number, because the mean of its divisors is an integer number (57463413).

Almost surely, 2^213435521 is an apocalyptic number.

It is an amenable number.

213435521 is a deficient number, since it is larger than the sum of its proper divisors (16418131).

213435521 is a wasteful number, since it uses less digits than its factorization.

213435521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16418130.

The product of its digits is 3600, while the sum is 26.

The square root of 213435521 is about 14609.4326036298. The cubic root of 213435521 is about 597.6160227065.

Adding to 213435521 its reverse (125534312), we get a palindrome (338969833).

The spelling of 213435521 in words is "two hundred thirteen million, four hundred thirty-five thousand, five hundred twenty-one".