217406487168 has 192 divisors, whose sum is σ = 690168122280. Its totient is φ = 65262551040.

The previous prime is 217406487139. The next prime is 217406487173. The reversal of 217406487168 is 861784604712.

217406487168 is a `hidden beast` number, since 217 + 406 + 4 + 8 + 7 + 16 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 30720273984 + 186686213184 = 175272^2 + 432072^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 436980 + ... + 791052.

Almost surely, 2^217406487168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217406487168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345084061140).

217406487168 is an abundant number, since it is smaller than the sum of its proper divisors (472761635112).

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

217406487168 is a wasteful number, since it uses less digits than its factorization.

217406487168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354147 (or 354132 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 54.

The spelling of 217406487168 in words is "two hundred seventeen billion, four hundred six million, four hundred eighty-seven thousand, one hundred sixty-eight".