216221672117 has 4 divisors (see below), whose sum is σ = 235878187776. Its totient is φ = 196565156460.

The previous prime is 216221672111. The next prime is 216221672189. The reversal of 216221672117 is 711276122612.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216221672117 - 2⁴ = 216221672101 is a prime.

It is a super-2 number, since 2×216221672117² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216221672111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9828257813 + ... + 9828257834.

It is an arithmetic number, because the mean of its divisors is an integer number (58969546944).

Almost surely, 2^216221672117 is an apocalyptic number.

It is an amenable number.

216221672117 is a deficient number, since it is larger than the sum of its proper divisors (19656515659).

216221672117 is a wasteful number, since it uses less digits than its factorization.

216221672117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19656515658.

The product of its digits is 28224, while the sum is 38.

Adding to 216221672117 its reverse (711276122612), we get a palindrome (927497794729).

The spelling of 216221672117 in words is "two hundred sixteen billion, two hundred twenty-one million, six hundred seventy-two thousand, one hundred seventeen".