129216 has 28 divisors (see below), whose sum is σ = 342392. Its totient is φ = 43008.

The previous prime is 129209. The next prime is 129221. The reversal of 129216 is 612921.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

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

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 129192 and 129201.

It is an unprimeable number.

129216 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 3 ways as a sum of consecutive naturals, for example, 145 + ... + 528.

2¹²⁹²¹⁶ is an apocalyptic number.

129216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

129216 is an abundant number, since it is smaller than the sum of its proper divisors (213176).

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

129216 is an equidigital number, since it uses as much as digits as its factorization.

129216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 678 counting only the distinct ones).

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

The square root of 129216 is about 359.4662710186. The cubic root of 129216 is about 50.5559292776. Note that the first 3 decimals are identical.

It can be divided in two parts, 12 and 9216, that multiplied together give a cube (110592 = 48³).

The spelling of 129216 in words is "one hundred twenty-nine thousand, two hundred sixteen".