206431321 has 2 divisors, whose sum is σ = 206431322. Its totient is φ = 206431320.

The previous prime is 206431319. The next prime is 206431327. The reversal of 206431321 is 123134602.

206431321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163712025 + 42719296 = 12795^2 + 6536^2 .

It is a cyclic number.

It is not a de Polignac number, because 206431321 - 2¹ = 206431319 is a prime.

It is a super-2 number, since 2×206431321² = 85227780579610082, which contains 22 as substring.

Together with 206431319, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 206431292 and 206431301.

It is not a weakly prime, because it can be changed into another prime (206431327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103215660 + 103215661.

It is an arithmetic number, because the mean of its divisors is an integer number (103215661).

Almost surely, 2^206431321 is an apocalyptic number.

It is an amenable number.

206431321 is a deficient number, since it is larger than the sum of its proper divisors (1).

206431321 is an equidigital number, since it uses as much as digits as its factorization.

206431321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 206431321 is about 14367.7180164423. The cubic root of 206431321 is about 591.0059645738.

Adding to 206431321 its reverse (123134602), we get a palindrome (329565923).

The spelling of 206431321 in words is "two hundred six million, four hundred thirty-one thousand, three hundred twenty-one".