217028321280 has 336 divisors, whose sum is σ = 796595982624. Its totient is φ = 54468280320.

The previous prime is 217028321243. The next prime is 217028321329. The reversal of 217028321280 is 82123820712.

217028321280 is a `hidden beast` number, since 21 + 70 + 283 + 212 + 80 = 666.

It is a super-2 number, since 2×217028321280² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 6249565 + ... + 6284195.

Almost surely, 2^217028321280 is an apocalyptic number.

217028321280 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 217028321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (398297991312).

217028321280 is an abundant number, since it is smaller than the sum of its proper divisors (579567661344).

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

217028321280 is a wasteful number, since it uses less digits than its factorization.

217028321280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34685 (or 34658 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 217028321280 in words is "two hundred seventeen billion, twenty-eight million, three hundred twenty-one thousand, two hundred eighty".