2161723873 has 2 divisors, whose sum is σ = 2161723874. Its totient is φ = 2161723872.

The previous prime is 2161723871. The next prime is 2161723901. The reversal of 2161723873 is 3783271612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1601360289 + 560363584 = 40017^2 + 23672^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161723873 - 2¹ = 2161723871 is a prime.

Together with 2161723871, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2161723871) 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 as a sum of consecutive naturals, namely, 1080861936 + 1080861937.

It is an arithmetic number, because the mean of its divisors is an integer number (1080861937).

Almost surely, 2^2161723873 is an apocalyptic number.

It is an amenable number.

2161723873 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161723873 is an equidigital number, since it uses as much as digits as its factorization.

2161723873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 40.

The square root of 2161723873 is about 46494.3423762505. The cubic root of 2161723873 is about 1293.0046088528.

The spelling of 2161723873 in words is "two billion, one hundred sixty-one million, seven hundred twenty-three thousand, eight hundred seventy-three".