16509404 has 12 divisors (see below), whose sum is σ = 30412200. Its totient is φ = 7820208.

The previous prime is 16509379. The next prime is 16509407. The reversal of 16509404 is 40490561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16509407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108539 + ... + 108690.

It is an arithmetic number, because the mean of its divisors is an integer number (2534350).

Almost surely, 2^16509404 is an apocalyptic number.

It is an amenable number.

16509404 is a deficient number, since it is larger than the sum of its proper divisors (13902796).

16509404 is a wasteful number, since it uses less digits than its factorization.

16509404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217252 (or 217250 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 16509404 is about 4063.1765898125. The cubic root of 16509404 is about 254.6305247664.

Adding to 16509404 its reverse (40490561), we get a palindrome (56999965).

The spelling of 16509404 in words is "sixteen million, five hundred nine thousand, four hundred four".