217021966848 has 160 divisors (see below), whose sum is σ = 663123985920. Its totient is φ = 70006947840.

The previous prime is 217021966829. The next prime is 217021966897. The reversal of 217021966848 is 848669120712.

It is a happy number.

It is a super-2 number, since 2×217021966848² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 217021966794 and 217021966803.

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 15 ways as a sum of consecutive naturals, for example, 175336 + ... + 681752.

It is an arithmetic number, because the mean of its divisors is an integer number (4144524912).

Almost surely, 2^217021966848 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 217021966848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331561992960).

217021966848 is an abundant number, since it is smaller than the sum of its proper divisors (446102019072).

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

217021966848 is an equidigital number, since it uses as much as digits as its factorization.

217021966848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506475 (or 506453 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The spelling of 217021966848 in words is "two hundred seventeen billion, twenty-one million, nine hundred sixty-six thousand, eight hundred forty-eight".