16561808 has 20 divisors (see below), whose sum is σ = 33976620. Its totient is φ = 7793664.

The previous prime is 16561799. The next prime is 16561819. The reversal of 16561808 is 80816561.

It can be written as a sum of positive squares in 2 ways, for example, as 6012304 + 10549504 = 2452^2 + 3248^2 .

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 30173 + ... + 30716.

It is an arithmetic number, because the mean of its divisors is an integer number (1698831).

Almost surely, 2^16561808 is an apocalyptic number.

It is an amenable number.

16561808 is an abundant number, since it is smaller than the sum of its proper divisors (17414812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16561808 is a wasteful number, since it uses less digits than its factorization.

16561808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60914 (or 60908 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 16561808 is about 4069.6201296927. The cubic root of 16561808 is about 254.8996555079.

The spelling of 16561808 in words is "sixteen million, five hundred sixty-one thousand, eight hundred eight".