16390305 has 24 divisors (see below), whose sum is σ = 28507752. Its totient is φ = 8711424.

The previous prime is 16390301. The next prime is 16390321. The reversal of 16390305 is 50309361.

It can be written as a sum of positive squares in 4 ways, for example, as 4028049 + 12362256 = 2007^2 + 3516^2 .

It is not a de Polignac number, because 16390305 - 2² = 16390301 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16390301) 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 23 ways as a sum of consecutive naturals, for example, 20167 + ... + 20963.

It is an arithmetic number, because the mean of its divisors is an integer number (1187823).

Almost surely, 2^16390305 is an apocalyptic number.

16390305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16390305 is a deficient number, since it is larger than the sum of its proper divisors (12117447).

16390305 is a wasteful number, since it uses less digits than its factorization.

16390305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1265 (or 1262 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 27.

The square root of 16390305 is about 4048.4941645012. The cubic root of 16390305 is about 254.0167440963.

Adding to 16390305 its reverse (50309361), we get a palindrome (66699666).

The spelling of 16390305 in words is "sixteen million, three hundred ninety thousand, three hundred five".