217221254020 has 24 divisors (see below), whose sum is σ = 480173299200. Its totient is φ = 82315422432.

The previous prime is 217221253961. The next prime is 217221254051. The reversal of 217221254020 is 20452122712.

It is a self number, because there is not a number n which added to its sum of digits gives 217221254020.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285817060 + ... + 285817819.

It is an arithmetic number, because the mean of its divisors is an integer number (20007220800).

Almost surely, 2^217221254020 is an apocalyptic number.

217221254020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217221254020 is an abundant number, since it is smaller than the sum of its proper divisors (262952045180).

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

217221254020 is a wasteful number, since it uses less digits than its factorization.

217221254020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571634907 (or 571634905 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

Adding to 217221254020 its reverse (20452122712), we get a palindrome (237673376732).

The spelling of 217221254020 in words is "two hundred seventeen billion, two hundred twenty-one million, two hundred fifty-four thousand, twenty".