217630985379840 has 1344 divisors, whose sum is σ = 796868323130880. Its totient is φ = 56967797145600.

The previous prime is 217630985379763. The next prime is 217630985379853. The reversal of 217630985379840 is 48973589036712.

217630985379840 is a `hidden beast` number, since 2 + 1 + 7 + 6 + 3 + 0 + 9 + 8 + 537 + 9 + 84 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 133762129107 + ... + 133762130733.

It is an arithmetic number, because the mean of its divisors is an integer number (592907978520).

It is a 2-persistent number, because it is pandigital, and so is 2⋅217630985379840 = 435261970759680, but 3⋅217630985379840 = 652892956139520 is not.

Almost surely, 2^{217630985379840} is an apocalyptic number.

217630985379840 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 217630985379840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (398434161565440).

217630985379840 is an abundant number, since it is smaller than the sum of its proper divisors (579237337751040).

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

217630985379840 is an equidigital number, since it uses as much as digits as its factorization.

217630985379840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1913 (or 1877 counting only the distinct ones).

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

The spelling of 217630985379840 in words is "two hundred seventeen trillion, six hundred thirty billion, nine hundred eighty-five million, three hundred seventy-nine thousand, eight hundred forty".