161688384 has 252 divisors, whose sum is σ = 551090592. Its totient is φ = 44928000.

The previous prime is 161688349. The next prime is 161688421. The reversal of 161688384 is 483886161.

It is a happy number.

It is a super-2 number, since 2×161688384² = 52286267041062912, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1070709 + ... + 1070859.

Almost surely, 2^161688384 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161688384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275545296).

161688384 is an abundant number, since it is smaller than the sum of its proper divisors (389402208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161688384 is a wasteful number, since it uses less digits than its factorization.

161688384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 180 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 161688384 is about 12715.6747363245. The cubic root of 161688384 is about 544.7864202532.

It can be divided in two parts, 1616 and 88384, that added together give a square (90000 = 300²).

The spelling of 161688384 in words is "one hundred sixty-one million, six hundred eighty-eight thousand, three hundred eighty-four".