2178956771 has 2 divisors, whose sum is σ = 2178956772. Its totient is φ = 2178956770.

The previous prime is 2178956743. The next prime is 2178956777. The reversal of 2178956771 is 1776598712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2178956771 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (2178956777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1089478385 + 1089478386.

It is an arithmetic number, because the mean of its divisors is an integer number (1089478386).

Almost surely, 2^2178956771 is an apocalyptic number.

2178956771 is a deficient number, since it is larger than the sum of its proper divisors (1).

2178956771 is an equidigital number, since it uses as much as digits as its factorization.

2178956771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1481760, while the sum is 53.

The square root of 2178956771 is about 46679.2970276974. The cubic root of 2178956771 is about 1296.4313905423.

The spelling of 2178956771 in words is "two billion, one hundred seventy-eight million, nine hundred fifty-six thousand, seven hundred seventy-one".