216251660 has 48 divisors (see below), whose sum is σ = 477695232. Its totient is φ = 82118400.

The previous prime is 216251657. The next prime is 216251689. The reversal of 216251660 is 66152612.

216251660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29570 + ... + 36150.

It is an arithmetic number, because the mean of its divisors is an integer number (9951984).

Almost surely, 2^216251660 is an apocalyptic number.

216251660 is a gapful number since it is divisible by the number (20) 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 216251660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238847616).

216251660 is an abundant number, since it is smaller than the sum of its proper divisors (261443572).

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

216251660 is a wasteful number, since it uses less digits than its factorization.

216251660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6674 (or 6672 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 216251660 is about 14705.4976114377. The cubic root of 216251660 is about 600.2329280810.

The spelling of 216251660 in words is "two hundred sixteen million, two hundred fifty-one thousand, six hundred sixty".