1216111171 has 8 divisors (see below), whose sum is σ = 1346468544. Its totient is φ = 1089054120.

The previous prime is 1216111157. The next prime is 1216111241. The reversal of 1216111171 is 1711116121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1216111171 - 2¹⁵ = 1216078403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216111271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 824305 + ... + 825778.

It is an arithmetic number, because the mean of its divisors is an integer number (168308568).

Almost surely, 2^1216111171 is an apocalyptic number.

1216111171 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1216111171 is a deficient number, since it is larger than the sum of its proper divisors (130357373).

1216111171 is a wasteful number, since it uses less digits than its factorization.

1216111171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1650161.

The product of its digits is 84, while the sum is 22.

The square root of 1216111171 is about 34872.7855354286. The cubic root of 1216111171 is about 1067.3931857870.

Multiplying 1216111171 by its sum of digits (22), we get a palindrome (26754445762).

Adding to 1216111171 its reverse (1711116121), we get a palindrome (2927227292).

It can be divided in two parts, 12161 and 11171, that added together give a palindrome (23332).

The spelling of 1216111171 in words is "one billion, two hundred sixteen million, one hundred eleven thousand, one hundred seventy-one".