221055215817 has 16 divisors (see below), whose sum is σ = 315339053120. Its totient is φ = 137325067200.

The previous prime is 221055215749. The next prime is 221055215833. The reversal of 221055215817 is 718512550122.

It is a happy number.

It is not a de Polignac number, because 221055215817 - 2¹⁴ = 221055199433 is a prime.

It is a super-4 number, since 4×221055215817⁴ (a number of 46 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221055215417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31784734 + ... + 31791687.

It is an arithmetic number, because the mean of its divisors is an integer number (19708690820).

Almost surely, 2^221055215817 is an apocalyptic number.

It is an amenable number.

221055215817 is a deficient number, since it is larger than the sum of its proper divisors (94283837303).

221055215817 is a wasteful number, since it uses less digits than its factorization.

221055215817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63576504.

The product of its (nonzero) digits is 56000, while the sum is 39.

Adding to 221055215817 its reverse (718512550122), we get a palindrome (939567765939).

The spelling of 221055215817 in words is "two hundred twenty-one billion, fifty-five million, two hundred fifteen thousand, eight hundred seventeen".