161801072 has 20 divisors (see below), whose sum is σ = 320161056. Its totient is φ = 79178880.

The previous prime is 161801071. The next prime is 161801077. The reversal of 161801072 is 270108161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161801071) 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 3 ways as a sum of consecutive naturals, for example, 106829 + ... + 108332.

Almost surely, 2^161801072 is an apocalyptic number.

It is an amenable number.

161801072 is a deficient number, since it is larger than the sum of its proper divisors (158359984).

161801072 is a wasteful number, since it uses less digits than its factorization.

161801072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215216 (or 215210 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 161801072 is about 12720.1050310129. The cubic root of 161801072 is about 544.9129530196.

The spelling of 161801072 in words is "one hundred sixty-one million, eight hundred one thousand, seventy-two".