406565321 has 2 divisors, whose sum is σ = 406565322. Its totient is φ = 406565320.

The previous prime is 406565309. The next prime is 406565323. The reversal of 406565321 is 123565604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 259210000 + 147355321 = 16100^2 + 12139^2 .

It is a cyclic number.

It is not a de Polignac number, because 406565321 - 2²⁶ = 339456457 is a prime.

Together with 406565323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (406565323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203282660 + 203282661.

It is an arithmetic number, because the mean of its divisors is an integer number (203282661).

Almost surely, 2^406565321 is an apocalyptic number.

It is an amenable number.

406565321 is a deficient number, since it is larger than the sum of its proper divisors (1).

406565321 is an equidigital number, since it uses as much as digits as its factorization.

406565321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 406565321 is about 20163.4650048051. The cubic root of 406565321 is about 740.8155854387.

The spelling of 406565321 in words is "four hundred six million, five hundred sixty-five thousand, three hundred twenty-one".