2161723937 has 4 divisors (see below), whose sum is σ = 2186013060. Its totient is φ = 2137434816.

The previous prime is 2161723919. The next prime is 2161723939. The reversal of 2161723937 is 7393271612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 549621136 + 1612102801 = 23444^2 + 40151^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161723937 - 2⁶ = 2161723873 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2161723894 and 2161723903.

It is not an unprimeable number, because it can be changed into a prime (2161723939) 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 3 ways as a sum of consecutive naturals, for example, 12144428 + ... + 12144605.

It is an arithmetic number, because the mean of its divisors is an integer number (546503265).

Almost surely, 2^2161723937 is an apocalyptic number.

It is an amenable number.

2161723937 is a deficient number, since it is larger than the sum of its proper divisors (24289123).

2161723937 is an equidigital number, since it uses as much as digits as its factorization.

2161723937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24289122.

The product of its digits is 95256, while the sum is 41.

The square root of 2161723937 is about 46494.3430645062. The cubic root of 2161723937 is about 1293.0046216130.

It can be divided in two parts, 21617 and 23937, that added together give a palindrome (45554).

The spelling of 2161723937 in words is "two billion, one hundred sixty-one million, seven hundred twenty-three thousand, nine hundred thirty-seven".