169491609 has 40 divisors (see below), whose sum is σ = 304610240. Its totient is φ = 91749024.

The previous prime is 169491587. The next prime is 169491629. The reversal of 169491609 is 906194961.

It is not a de Polignac number, because 169491609 - 2⁷ = 169491481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (169491629) 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 39 ways as a sum of consecutive naturals, for example, 2907 + ... + 18639.

It is an arithmetic number, because the mean of its divisors is an integer number (7615256).

Almost surely, 2^169491609 is an apocalyptic number.

169491609 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

169491609 is a deficient number, since it is larger than the sum of its proper divisors (135118631).

169491609 is a wasteful number, since it uses less digits than its factorization.

169491609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15771 (or 15762 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 169491609 is about 13018.8943078896. The cubic root of 169491609 is about 553.4130561653.

The spelling of 169491609 in words is "one hundred sixty-nine million, four hundred ninety-one thousand, six hundred nine".