2161221117 has 8 divisors (see below), whose sum is σ = 3143594400. Its totient is φ = 1309830960.

The previous prime is 2161221113. The next prime is 2161221131. The reversal of 2161221117 is 7111221612.

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

It is not a de Polignac number, because 2161221117 - 2² = 2161221113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161221113) by changing a digit.

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, 32745742 + ... + 32745807.

It is an arithmetic number, because the mean of its divisors is an integer number (392949300).

Almost surely, 2^2161221117 is an apocalyptic number.

It is an amenable number.

2161221117 is a deficient number, since it is larger than the sum of its proper divisors (982373283).

2161221117 is a wasteful number, since it uses less digits than its factorization.

2161221117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65491563.

The product of its digits is 336, while the sum is 24.

The square root of 2161221117 is about 46488.9354255397. The cubic root of 2161221117 is about 1292.9043622802.

Adding to 2161221117 its reverse (7111221612), we get a palindrome (9272442729).

The spelling of 2161221117 in words is "two billion, one hundred sixty-one million, two hundred twenty-one thousand, one hundred seventeen".