8121641771 has 2 divisors, whose sum is σ = 8121641772. Its totient is φ = 8121641770.

The previous prime is 8121641753. The next prime is 8121641819. The reversal of 8121641771 is 1771461218.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8121641771 is a prime.

It is a super-2 number, since 2×8121641771² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (8121647771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4060820885 + 4060820886.

It is an arithmetic number, because the mean of its divisors is an integer number (4060820886).

Almost surely, 2^8121641771 is an apocalyptic number.

8121641771 is a deficient number, since it is larger than the sum of its proper divisors (1).

8121641771 is an equidigital number, since it uses as much as digits as its factorization.

8121641771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816, while the sum is 38.

The square root of 8121641771 is about 90120.1518585050. The cubic root of 8121641771 is about 2010.0858664010.

The spelling of 8121641771 in words is "eight billion, one hundred twenty-one million, six hundred forty-one thousand, seven hundred seventy-one".