16172809 has 2 divisors, whose sum is σ = 16172810. Its totient is φ = 16172808.

The previous prime is 16172803. The next prime is 16172833. The reversal of 16172809 is 90827161.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15721225 + 451584 = 3965^2 + 672^2 .

It is a cyclic number.

It is not a de Polignac number, because 16172809 - 2⁵ = 16172777 is a prime.

It is not a weakly prime, because it can be changed into another prime (16172803) 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 as a sum of consecutive naturals, namely, 8086404 + 8086405.

It is an arithmetic number, because the mean of its divisors is an integer number (8086405).

Almost surely, 2^16172809 is an apocalyptic number.

It is an amenable number.

16172809 is a deficient number, since it is larger than the sum of its proper divisors (1).

16172809 is an equidigital number, since it uses as much as digits as its factorization.

16172809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 16172809 is about 4021.5431117918. The cubic root of 16172809 is about 252.8881537837. Note that the first 3 decimals are identical.

The spelling of 16172809 in words is "sixteen million, one hundred seventy-two thousand, eight hundred nine".