217386880 has 64 divisors (see below), whose sum is σ = 536503680. Its totient is φ = 84142080.

The previous prime is 217386839. The next prime is 217386881. The reversal of 217386880 is 88683712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×217386880² = 94514111192268800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217386881) 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 7 ways as a sum of consecutive naturals, for example, 14362 + ... + 25318.

It is an arithmetic number, because the mean of its divisors is an integer number (8382870).

Almost surely, 2^217386880 is an apocalyptic number.

217386880 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 217386880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268251840).

217386880 is an abundant number, since it is smaller than the sum of its proper divisors (319116800).

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

217386880 is a wasteful number, since it uses less digits than its factorization.

217386880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11007 (or 10995 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 217386880 is about 14744.0455777917. The cubic root of 217386880 is about 601.2814095160.

The spelling of 217386880 in words is "two hundred seventeen million, three hundred eighty-six thousand, eight hundred eighty".