217720961832 has 48 divisors (see below), whose sum is σ = 598282816320. Its totient is φ = 65976048160.

The previous prime is 217720961831. The next prime is 217720961849. The reversal of 217720961832 is 238169027712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (217720961831) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37483488 + ... + 37489295.

It is an arithmetic number, because the mean of its divisors is an integer number (12464225340).

Almost surely, 2^217720961832 is an apocalyptic number.

217720961832 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

217720961832 is an abundant number, since it is smaller than the sum of its proper divisors (380561854488).

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

217720961832 is a wasteful number, since it uses less digits than its factorization.

217720961832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74972814 (or 74972799 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The spelling of 217720961832 in words is "two hundred seventeen billion, seven hundred twenty million, nine hundred sixty-one thousand, eight hundred thirty-two".