205021213 has 8 divisors (see below), whose sum is σ = 214193880. Its totient is φ = 195988800.

The previous prime is 205021199. The next prime is 205021231. The reversal of 205021213 is 312120502.

It can be written as a sum of positive squares in 4 ways, for example, as 122810724 + 82210489 = 11082^2 + 9067^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205021213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205021613) 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 7 ways as a sum of consecutive naturals, for example, 32070 + ... + 37927.

It is an arithmetic number, because the mean of its divisors is an integer number (26774235).

Almost surely, 2^205021213 is an apocalyptic number.

It is an amenable number.

205021213 is a deficient number, since it is larger than the sum of its proper divisors (9172667).

205021213 is a wasteful number, since it uses less digits than its factorization.

205021213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70127.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 205021213 is about 14318.5618342067. The cubic root of 205021213 is about 589.6571914526.

Adding to 205021213 its reverse (312120502), we get a palindrome (517141715).

The spelling of 205021213 in words is "two hundred five million, twenty-one thousand, two hundred thirteen".