205521213 has 16 divisors (see below), whose sum is σ = 278510400. Its totient is φ = 134791296.

The previous prime is 205521193. The next prime is 205521221. The reversal of 205521213 is 312125502.

It is not a de Polignac number, because 205521213 - 2⁵ = 205521181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205521213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205521263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45681 + ... + 49977.

It is an arithmetic number, because the mean of its divisors is an integer number (17406900).

Almost surely, 2^205521213 is an apocalyptic number.

It is an amenable number.

205521213 is a deficient number, since it is larger than the sum of its proper divisors (72989187).

205521213 is a wasteful number, since it uses less digits than its factorization.

205521213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4556.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 205521213 is about 14336.0110560783. The cubic root of 205521213 is about 590.1361487962.

Adding to 205521213 its reverse (312125502), we get a palindrome (517646715).

The spelling of 205521213 in words is "two hundred five million, five hundred twenty-one thousand, two hundred thirteen".