161722099 has 16 divisors (see below), whose sum is σ = 205747200. Its totient is φ = 126014280.

The previous prime is 161722087. The next prime is 161722117. The reversal of 161722099 is 990227161.

It is not a de Polignac number, because 161722099 - 2⁹ = 161721587 is a prime.

It is a Duffinian number.

161722099 is a modest number, since divided by 22099 gives 1617 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161722019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17659 + ... + 25204.

It is an arithmetic number, because the mean of its divisors is an integer number (12859200).

Almost surely, 2^161722099 is an apocalyptic number.

161722099 is a deficient number, since it is larger than the sum of its proper divisors (44025101).

161722099 is an equidigital number, since it uses as much as digits as its factorization.

161722099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42895 (or 42881 counting only the distinct ones).

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

The square root of 161722099 is about 12717.0003931745. Note that the first 3 decimals coincide. The cubic root of 161722099 is about 544.8242836156.

It can be divided in two parts, 1617 and 22099, that added together give a square (23716 = 154²).

The spelling of 161722099 in words is "one hundred sixty-one million, seven hundred twenty-two thousand, ninety-nine".