216680646 has 120 divisors (see below), whose sum is σ = 553589640. Its totient is φ = 56504448.

The previous prime is 216680641. The next prime is 216680683. The reversal of 216680646 is 646086612.

216680646 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216680641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2434570 + ... + 2434658.

It is an arithmetic number, because the mean of its divisors is an integer number (4613247).

Almost surely, 2^216680646 is an apocalyptic number.

216680646 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 216680646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276794820).

216680646 is an abundant number, since it is smaller than the sum of its proper divisors (336908994).

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

216680646 is an equidigital number, since it uses as much as digits as its factorization.

216680646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 216680646 is about 14720.0762905632. The cubic root of 216680646 is about 600.6295669558.

The spelling of 216680646 in words is "two hundred sixteen million, six hundred eighty thousand, six hundred forty-six".