161864 has 8 divisors (see below), whose sum is σ = 303510. Its totient is φ = 80928.

The previous prime is 161839. The next prime is 161869. The reversal of 161864 is 468161.

It can be written as a sum of positive squares in only one way, i.e., 136900 + 24964 = 370^2 + 158^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (161869) by changing a digit.

161864 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 10109 + ... + 10124.

2¹⁶¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

161864 is a deficient number, since it is larger than the sum of its proper divisors (141646).

161864 is a wasteful number, since it uses less digits than its factorization.

161864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20239 (or 20235 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 161864 is about 402.3232531187. The cubic root of 161864 is about 54.4983586746.

The spelling of 161864 in words is "one hundred sixty-one thousand, eight hundred sixty-four".