16717121 has 4 divisors (see below), whose sum is σ = 16729812. Its totient is φ = 16704432.

The previous prime is 16717109. The next prime is 16717139. The reversal of 16717121 is 12171761.

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 9486400 + 7230721 = 3080^2 + 2689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16717121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16707121) 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 in 3 ways as a sum of consecutive naturals, for example, 4106 + ... + 7091.

It is an arithmetic number, because the mean of its divisors is an integer number (4182453).

Almost surely, 2^16717121 is an apocalyptic number.

It is an amenable number.

16717121 is a deficient number, since it is larger than the sum of its proper divisors (12691).

16717121 is a wasteful number, since it uses less digits than its factorization.

16717121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12690.

The product of its digits is 588, while the sum is 26.

The square root of 16717121 is about 4088.6576036641. The cubic root of 16717121 is about 255.6939753450.

Adding to 16717121 its reverse (12171761), we get a palindrome (28888882).

The spelling of 16717121 in words is "sixteen million, seven hundred seventeen thousand, one hundred twenty-one".