217047617920 has 256 divisors, whose sum is σ = 607964227200. Its totient is φ = 72562507776.

The previous prime is 217047617911. The next prime is 217047617921. The reversal of 217047617920 is 29716740712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217047617921) 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, 29102832 + ... + 29110288.

Almost surely, 2^217047617920 is an apocalyptic number.

217047617920 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 217047617920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303982113600).

217047617920 is an abundant number, since it is smaller than the sum of its proper divisors (390916609280).

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

217047617920 is an equidigital number, since it uses as much as digits as its factorization.

217047617920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7645 (or 7633 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 46.

The spelling of 217047617920 in words is "two hundred seventeen billion, forty-seven million, six hundred seventeen thousand, nine hundred twenty".