217854749128 has 32 divisors (see below), whose sum is σ = 409100605560. Its totient is φ = 108761356800.

The previous prime is 217854749111. The next prime is 217854749137. The reversal of 217854749128 is 821947458712.

217854749128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 217695030084 + 159719044 = 466578^2 + 12638^2 .

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 7 ways as a sum of consecutive naturals, for example, 26888278 + ... + 26896378.

Almost surely, 2^217854749128 is an apocalyptic number.

It is an amenable number.

217854749128 is a deficient number, since it is larger than the sum of its proper divisors (191245856432).

217854749128 is a wasteful number, since it uses less digits than its factorization.

217854749128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12817 (or 12813 counting only the distinct ones).

The product of its digits is 9031680, while the sum is 58.

The spelling of 217854749128 in words is "two hundred seventeen billion, eight hundred fifty-four million, seven hundred forty-nine thousand, one hundred twenty-eight".