217892456768 has 448 divisors, whose sum is σ = 550298112000. Its totient is φ = 85349376000.

The previous prime is 217892456713. The next prime is 217892456783. The reversal of 217892456768 is 867654298712.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Smith number, since the sum of its digits (65) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1203825638 + ... + 1203825818.

It is an arithmetic number, because the mean of its divisors is an integer number (1228344000).

Almost surely, 2^217892456768 is an apocalyptic number.

217892456768 is a gapful number since it is divisible by the number (28) 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 217892456768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275149056000).

217892456768 is an abundant number, since it is smaller than the sum of its proper divisors (332405655232).

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

217892456768 is a wasteful number, since it uses less digits than its factorization.

217892456768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335 (or 311 counting only the distinct ones).

The product of its digits is 81285120, while the sum is 65.

The spelling of 217892456768 in words is "two hundred seventeen billion, eight hundred ninety-two million, four hundred fifty-six thousand, seven hundred sixty-eight".