216817770 has 64 divisors (see below), whose sum is σ = 563915520. Its totient is φ = 53035008.

The previous prime is 216817723. The next prime is 216817789. The reversal of 216817770 is 77718612.

216817770 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×216817770³ (a number of 26 digits) contains 333 as substring.

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

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 63466 + ... + 66794.

It is an arithmetic number, because the mean of its divisors is an integer number (8811180).

Almost surely, 2^216817770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216817770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281957760).

216817770 is an abundant number, since it is smaller than the sum of its proper divisors (347097750).

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

216817770 is a wasteful number, since it uses less digits than its factorization.

216817770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3519.

The product of its (nonzero) digits is 32928, while the sum is 39.

The square root of 216817770 is about 14724.7332743245. The cubic root of 216817770 is about 600.7562408769.

The spelling of 216817770 in words is "two hundred sixteen million, eight hundred seventeen thousand, seven hundred seventy".