16009505 has 4 divisors (see below), whose sum is σ = 19211412. Its totient is φ = 12807600.

The previous prime is 16009489. The next prime is 16009507. The reversal of 16009505 is 50590061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50590061 = 109 ⋅464129.

It can be written as a sum of positive squares in 2 ways, for example, as 6822544 + 9186961 = 2612^2 + 3031^2 .

It is not a de Polignac number, because 16009505 - 2⁴ = 16009489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16009507) 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, 1600946 + ... + 1600955.

It is an arithmetic number, because the mean of its divisors is an integer number (4802853).

Almost surely, 2^16009505 is an apocalyptic number.

It is an amenable number.

16009505 is a deficient number, since it is larger than the sum of its proper divisors (3201907).

16009505 is an equidigital number, since it uses as much as digits as its factorization.

16009505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3201906.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 16009505 is about 4001.1879485973. The cubic root of 16009505 is about 252.0340982246.

Adding to 16009505 its reverse (50590061), we get a palindrome (66599566).

The spelling of 16009505 in words is "sixteen million, nine thousand, five hundred five".