217193857066368 has 3072 divisors, whose sum is σ = 872553369600000. Its totient is φ = 52965091565568.

The previous prime is 217193857066313. The next prime is 217193857066399. The reversal of 217193857066368 is 863660758391712.

It is a happy number.

217193857066368 is a `hidden beast` number, since 2 + 1 + 7 + 19 + 3 + 8 + 570 + 6 + 6 + 36 + 8 = 666.

It is a super-2 number, since 2×217193857066368² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 217193857066296 and 217193857066305.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 163672838121 + ... + 163672839447.

It is an arithmetic number, because the mean of its divisors is an integer number (284034300000).

Almost surely, 2^{217193857066368} is an apocalyptic number.

217193857066368 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 217193857066368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436276684800000).

217193857066368 is an abundant number, since it is smaller than the sum of its proper divisors (655359512533632).

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

217193857066368 is a wasteful number, since it uses less digits than its factorization.

217193857066368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1459 (or 1414 counting only the distinct ones).

The product of its (nonzero) digits is 548674560, while the sum is 72.

The spelling of 217193857066368 in words is "two hundred seventeen trillion, one hundred ninety-three billion, eight hundred fifty-seven million, sixty-six thousand, three hundred sixty-eight".