2161744591 has 4 divisors (see below), whose sum is σ = 2162440800. Its totient is φ = 2161048384.

The previous prime is 2161744567. The next prime is 2161744661. The reversal of 2161744591 is 1954471612.

It is a happy number.

2161744591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2161744591 - 2¹¹ = 2161742543 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 (2161744561) 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, 343426 + ... + 349663.

It is an arithmetic number, because the mean of its divisors is an integer number (540610200).

Almost surely, 2^2161744591 is an apocalyptic number.

2161744591 is a deficient number, since it is larger than the sum of its proper divisors (696209).

2161744591 is an equidigital number, since it uses as much as digits as its factorization.

2161744591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696208.

The product of its digits is 60480, while the sum is 40.

The square root of 2161744591 is about 46494.5651770183. The cubic root of 2161744591 is about 1293.0087395659.

The spelling of 2161744591 in words is "two billion, one hundred sixty-one million, seven hundred forty-four thousand, five hundred ninety-one".