2161181789 has 8 divisors (see below), whose sum is σ = 2328988032. Its totient is φ = 1993598640.

The previous prime is 2161181779. The next prime is 2161181837. The reversal of 2161181789 is 9871811612.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161181789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161181779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35369 + ... + 74654.

It is an arithmetic number, because the mean of its divisors is an integer number (291123504).

Almost surely, 2^2161181789 is an apocalyptic number.

It is an amenable number.

2161181789 is a deficient number, since it is larger than the sum of its proper divisors (167806243).

2161181789 is a wasteful number, since it uses less digits than its factorization.

2161181789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111547.

The product of its digits is 48384, while the sum is 44.

The square root of 2161181789 is about 46488.5124412472. The cubic root of 2161181789 is about 1292.8965198540.

The spelling of 2161181789 in words is "two billion, one hundred sixty-one million, one hundred eighty-one thousand, seven hundred eighty-nine".