217928272947840 has 6144 divisors, whose sum is σ = 1040639789629440. Its totient is φ = 40772616192000.

The previous prime is 217928272947811. The next prime is 217928272947881. The reversal of 217928272947840 is 48749272829712.

217928272947840 is a `hidden beast` number, since 2 + 1 + 7 + 9 + 2 + 82 + 72 + 9 + 478 + 4 + 0 = 666.

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

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 767 ways as a sum of consecutive naturals, for example, 1140985722145 + ... + 1140985722335.

It is an arithmetic number, because the mean of its divisors is an integer number (169374965760).

Almost surely, 2^{217928272947840} is an apocalyptic number.

217928272947840 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 217928272947840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (520319894814720).

217928272947840 is an abundant number, since it is smaller than the sum of its proper divisors (822711516681600).

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

217928272947840 is a wasteful number, since it uses less digits than its factorization.

217928272947840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 455196672, while the sum is 72.

The spelling of 217928272947840 in words is "two hundred seventeen trillion, nine hundred twenty-eight billion, two hundred seventy-two million, nine hundred forty-seven thousand, eight hundred forty".