205214021 has 8 divisors (see below), whose sum is σ = 217413144. Its totient is φ = 193029120.

The previous prime is 205213997. The next prime is 205214047. The reversal of 205214021 is 120412502.

It can be written as a sum of positive squares in 4 ways, for example, as 102921025 + 102292996 = 10145^2 + 10114^2 .

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-205214021 is a prime.

It is a super-2 number, since 2×205214021² = 84225588829976882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205214521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46031 + ... + 50291.

It is an arithmetic number, because the mean of its divisors is an integer number (27176643).

Almost surely, 2^205214021 is an apocalyptic number.

It is an amenable number.

205214021 is a deficient number, since it is larger than the sum of its proper divisors (12199123).

205214021 is a wasteful number, since it uses less digits than its factorization.

205214021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7111.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 205214021 is about 14325.2930511037. The cubic root of 205214021 is about 589.8419772143.

Adding to 205214021 its reverse (120412502), we get a palindrome (325626523).

It can be divided in two parts, 20521 and 4021, that added together give a palindrome (24542).

The spelling of 205214021 in words is "two hundred five million, two hundred fourteen thousand, twenty-one".