2171181641 has 2 divisors, whose sum is σ = 2171181642. Its totient is φ = 2171181640.

The previous prime is 2171181637. The next prime is 2171181643. The reversal of 2171181641 is 1461811712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2171094025 + 87616 = 46595^2 + 296^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171181641 - 2² = 2171181637 is a prime.

It is a Sophie Germain prime.

Together with 2171181643, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2171181598 and 2171181607.

It is not a weakly prime, because it can be changed into another prime (2171181643) 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, 1085590820 + 1085590821.

It is an arithmetic number, because the mean of its divisors is an integer number (1085590821).

Almost surely, 2^2171181641 is an apocalyptic number.

It is an amenable number.

2171181641 is a deficient number, since it is larger than the sum of its proper divisors (1).

2171181641 is an equidigital number, since it uses as much as digits as its factorization.

2171181641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 32.

The square root of 2171181641 is about 46595.9401772300. The cubic root of 2171181641 is about 1294.8875422984.

The spelling of 2171181641 in words is "two billion, one hundred seventy-one million, one hundred eighty-one thousand, six hundred forty-one".