16749109 has 4 divisors (see below), whose sum is σ = 18037516. Its totient is φ = 15460704.

The previous prime is 16749107. The next prime is 16749121. The reversal of 16749109 is 90194761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90194761 = 173 ⋅521357.

It can be written as a sum of positive squares in 2 ways, for example, as 1562500 + 15186609 = 1250^2 + 3897^2 .

It is a cyclic number.

It is not a de Polignac number, because 16749109 - 2¹ = 16749107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16749107) 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, 644184 + ... + 644209.

It is an arithmetic number, because the mean of its divisors is an integer number (4509379).

Almost surely, 2^16749109 is an apocalyptic number.

It is an amenable number.

16749109 is a deficient number, since it is larger than the sum of its proper divisors (1288407).

16749109 is a wasteful number, since it uses less digits than its factorization.

16749109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288406.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 16749109 is about 4092.5675315137. The cubic root of 16749109 is about 255.8569604971.

The spelling of 16749109 in words is "sixteen million, seven hundred forty-nine thousand, one hundred nine".