213005543521 has 4 divisors (see below), whose sum is σ = 213542081812. Its totient is φ = 212469005232.

The previous prime is 213005543503. The next prime is 213005543573. The reversal of 213005543521 is 125345500312.

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 47652707025 + 165352836496 = 218295^2 + 406636^2 .

It is a cyclic number.

It is not a de Polignac number, because 213005543521 - 2¹¹ = 213005541473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213005543581) 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, 268268550 + ... + 268269343.

It is an arithmetic number, because the mean of its divisors is an integer number (53385520453).

Almost surely, 2^213005543521 is an apocalyptic number.

It is an amenable number.

213005543521 is a deficient number, since it is larger than the sum of its proper divisors (536538291).

213005543521 is an equidigital number, since it uses as much as digits as its factorization.

213005543521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536538290.

The product of its (nonzero) digits is 18000, while the sum is 31.

The spelling of 213005543521 in words is "two hundred thirteen billion, five million, five hundred forty-three thousand, five hundred twenty-one".