161616 has 80 divisors (see below), whose sum is σ = 527744. Its totient is φ = 41472.

The previous prime is 161611. The next prime is 161627. The reversal of 161616 is 616161.

161616 = T₈ + T₉ + ... + T₉₈.

161616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161616² = 52239462912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

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

161616 is an undulating number in base 10.

161616 is a modest number, since divided by 1616 gives 16 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 161592 and 161601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161611) by changing a digit.

161616 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4350 + ... + 4386.

2¹⁶¹⁶¹⁶ is an apocalyptic number.

161616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263872).

161616 is an abundant number, since it is smaller than the sum of its proper divisors (366128).

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

161616 is a wasteful number, since it uses less digits than its factorization.

161616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 62 counting only the distinct ones).

The product of its digits is 216, while the sum is 21.

The square root of 161616 is about 402.0149250961. The cubic root of 161616 is about 54.4705112194.

Adding to 161616 its reverse (616161), we get a palindrome (777777).

It can be divided in two parts, 161 and 616, that added together give a palindrome (777).

The spelling of 161616 in words is "one hundred sixty-one thousand, six hundred sixteen".