205740321 has 16 divisors (see below), whose sum is σ = 281335680. Its totient is φ = 133696640.

The previous prime is 205740319. The next prime is 205740361. The reversal of 205740321 is 123047502.

It is a cyclic number.

It is not a de Polignac number, because 205740321 - 2¹ = 205740319 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205740291 and 205740300.

It is not an unprimeable number, because it can be changed into a prime (205740361) 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 15 ways as a sum of consecutive naturals, for example, 13531 + ... + 24383.

It is an arithmetic number, because the mean of its divisors is an integer number (17583480).

Almost surely, 2^205740321 is an apocalyptic number.

It is an amenable number.

205740321 is a deficient number, since it is larger than the sum of its proper divisors (75595359).

205740321 is a wasteful number, since it uses less digits than its factorization.

205740321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11016.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 205740321 is about 14343.6508950825. The cubic root of 205740321 is about 590.3457907857.

Adding to 205740321 its reverse (123047502), we get a palindrome (328787823).

The spelling of 205740321 in words is "two hundred five million, seven hundred forty thousand, three hundred twenty-one".