217555193706648 has 128 divisors (see below), whose sum is σ = 644961986949120. Its totient is φ = 59841833287680.

The previous prime is 217555193706629. The next prime is 217555193706649. The reversal of 217555193706648 is 846607391555712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217555193706649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107215765 + ... + 109226052.

It is an arithmetic number, because the mean of its divisors is an integer number (5038765523040).

It is a 2-persistent number, because it is pandigital, and so is 2⋅217555193706648 = 435110387413296, but 3⋅217555193706648 = 652665581119944 is not.

Almost surely, 2^{217555193706648} is an apocalyptic number.

217555193706648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

217555193706648 is an abundant number, since it is smaller than the sum of its proper divisors (427406793242472).

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

217555193706648 is a wasteful number, since it uses less digits than its factorization.

217555193706648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216442057 (or 216442053 counting only the distinct ones).

The product of its (nonzero) digits is 381024000, while the sum is 69.

The spelling of 217555193706648 in words is "two hundred seventeen trillion, five hundred fifty-five billion, one hundred ninety-three million, seven hundred six thousand, six hundred forty-eight".