161720044 has 48 divisors (see below), whose sum is σ = 302141952. Its totient is φ = 75632832.

The previous prime is 161720017. The next prime is 161720047. The reversal of 161720044 is 440027161.

It is not an unprimeable number, because it can be changed into a prime (161720047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 465879 + ... + 466225.

It is an arithmetic number, because the mean of its divisors is an integer number (6294624).

Almost surely, 2^161720044 is an apocalyptic number.

It is an amenable number.

161720044 is a deficient number, since it is larger than the sum of its proper divisors (140421908).

161720044 is a wasteful number, since it uses less digits than its factorization.

161720044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 161720044 is about 12716.9195955624. The cubic root of 161720044 is about 544.8219759148.

The spelling of 161720044 in words is "one hundred sixty-one million, seven hundred twenty thousand, forty-four".