213421521 has 8 divisors (see below), whose sum is σ = 286152480. Its totient is φ = 141485792.

The previous prime is 213421511. The next prime is 213421529. The reversal of 213421521 is 125124312.

213421521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 213421521 - 2¹⁰ = 213420497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (213421529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198180 + ... + 199253.

It is an arithmetic number, because the mean of its divisors is an integer number (35769060).

Almost surely, 2^213421521 is an apocalyptic number.

It is an amenable number.

213421521 is a deficient number, since it is larger than the sum of its proper divisors (72730959).

213421521 is a wasteful number, since it uses less digits than its factorization.

213421521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397615.

The product of its digits is 480, while the sum is 21.

The square root of 213421521 is about 14608.9534532765. The cubic root of 213421521 is about 597.6029558293.

Adding to 213421521 its reverse (125124312), we get a palindrome (338545833).

The spelling of 213421521 in words is "two hundred thirteen million, four hundred twenty-one thousand, five hundred twenty-one".