161872 has 20 divisors (see below), whose sum is σ = 320416. Its totient is φ = 79200.

The previous prime is 161869. The next prime is 161873. The reversal of 161872 is 278161.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997 + ... + 1147.

2¹⁶¹⁸⁷² is an apocalyptic number.

It is an amenable number.

161872 is a deficient number, since it is larger than the sum of its proper divisors (158544).

161872 is a wasteful number, since it uses less digits than its factorization.

161872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 220 counting only the distinct ones).

The product of its digits is 672, while the sum is 25.

The square root of 161872 is about 402.3331952499. Note that the first 3 decimals coincide. The cubic root of 161872 is about 54.4992565059.

The spelling of 161872 in words is "one hundred sixty-one thousand, eight hundred seventy-two".