681216 has 36 divisors (see below), whose sum is σ = 1815072. Its totient is φ = 226816.

The previous prime is 681179. The next prime is 681221. The reversal of 681216 is 612186.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a nialpdrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 325 + ... + 1211.

2⁶⁸¹²¹⁶ 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 681216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907536).

681216 is an abundant number, since it is smaller than the sum of its proper divisors (1133856).

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

681216 is an equidigital number, since it uses as much as digits as its factorization.

681216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906 (or 892 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 681216 is about 825.3581040979. The cubic root of 681216 is about 87.9889793361.

The spelling of 681216 in words is "six hundred eighty-one thousand, two hundred sixteen".