16408400321 has 2 divisors, whose sum is σ = 16408400322. Its totient is φ = 16408400320.

The previous prime is 16408400273. The next prime is 16408400377. The reversal of 16408400321 is 12300480461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10725502096 + 5682898225 = 103564^2 + 75385^2 .

It is a cyclic number.

It is not a de Polignac number, because 16408400321 - 2¹⁸ = 16408138177 is a prime.

It is not a weakly prime, because it can be changed into another prime (16408400621) 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 as a sum of consecutive naturals, namely, 8204200160 + 8204200161.

It is an arithmetic number, because the mean of its divisors is an integer number (8204200161).

Almost surely, 2^16408400321 is an apocalyptic number.

It is an amenable number.

16408400321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16408400321 is an equidigital number, since it uses as much as digits as its factorization.

16408400321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 29.

Adding to 16408400321 its reverse (12300480461), we get a palindrome (28708880782).

The spelling of 16408400321 in words is "sixteen billion, four hundred eight million, four hundred thousand, three hundred twenty-one".