216981600 has 144 divisors (see below), whose sum is σ = 770575680. Its totient is φ = 52595200.

The previous prime is 216981599. The next prime is 216981607. The reversal of 216981600 is 6189612.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216981607) 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 23 ways as a sum of consecutive naturals, for example, 22291 + ... + 30509.

It is an arithmetic number, because the mean of its divisors is an integer number (5351220).

Almost surely, 2^216981600 is an apocalyptic number.

216981600 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 216981600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385287840).

216981600 is an abundant number, since it is smaller than the sum of its proper divisors (553594080).

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

216981600 is a wasteful number, since it uses less digits than its factorization.

216981600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8253 (or 8240 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 216981600 is about 14730.2953127220. The cubic root of 216981600 is about 600.9075155560.

The spelling of 216981600 in words is "two hundred sixteen million, nine hundred eighty-one thousand, six hundred".