16661329 has 4 divisors (see below), whose sum is σ = 16773300. Its totient is φ = 16549360.

The previous prime is 16661321. The next prime is 16661363. The reversal of 16661329 is 92316661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5452225 + 11209104 = 2335^2 + 3348^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661329 - 2³ = 16661321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16661294 and 16661303.

It is not an unprimeable number, because it can be changed into a prime (16661321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55762 + ... + 56059.

It is an arithmetic number, because the mean of its divisors is an integer number (4193325).

Almost surely, 2^16661329 is an apocalyptic number.

It is an amenable number.

16661329 is a deficient number, since it is larger than the sum of its proper divisors (111971).

16661329 is a wasteful number, since it uses less digits than its factorization.

16661329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111970.

The product of its digits is 11664, while the sum is 34.

The square root of 16661329 is about 4081.8291243020. The cubic root of 16661329 is about 255.4092058576.

The spelling of 16661329 in words is "sixteen million, six hundred sixty-one thousand, three hundred twenty-nine".