161908815 has 16 divisors (see below), whose sum is σ = 267411456. Its totient is φ = 83565600.

The previous prime is 161908801. The next prime is 161908819. The reversal of 161908815 is 518809161.

It is not a de Polignac number, because 161908815 - 2¹⁰ = 161907791 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161908819) 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 15 ways as a sum of consecutive naturals, for example, 173631 + ... + 174560.

It is an arithmetic number, because the mean of its divisors is an integer number (16713216).

Almost surely, 2^161908815 is an apocalyptic number.

161908815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161908815 is a deficient number, since it is larger than the sum of its proper divisors (105502641).

161908815 is a wasteful number, since it uses less digits than its factorization.

161908815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348230.

The product of its (nonzero) digits is 17280, while the sum is 39.

The square root of 161908815 is about 12724.3394720512. The cubic root of 161908815 is about 545.0338783193.

The spelling of 161908815 in words is "one hundred sixty-one million, nine hundred eight thousand, eight hundred fifteen".