405040321 has 6 divisors (see below), whose sum is σ = 471169410. Its totient is φ = 347177376.

The previous prime is 405040253. The next prime is 405040331. The reversal of 405040321 is 123040504.

It can be written as a sum of positive squares in only one way, i.e., 377330625 + 27709696 = 19425^2 + 5264^2 .

It is not a de Polignac number, because 405040321 - 2⁷ = 405040193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (405040331) 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 5 ways as a sum of consecutive naturals, for example, 4133016 + ... + 4133113.

It is an arithmetic number, because the mean of its divisors is an integer number (78528235).

Almost surely, 2^405040321 is an apocalyptic number.

It is an amenable number.

405040321 is a deficient number, since it is larger than the sum of its proper divisors (66129089).

405040321 is an equidigital number, since it uses as much as digits as its factorization.

405040321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8266143 (or 8266136 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 405040321 is about 20125.6135558646. The cubic root of 405040321 is about 739.8881746046. Note that the first 3 decimals are identical.

Adding to 405040321 its reverse (123040504), we get a palindrome (528080825).

The spelling of 405040321 in words is "four hundred five million, forty thousand, three hundred twenty-one".