19776809771 has 2 divisors, whose sum is σ = 19776809772. Its totient is φ = 19776809770.

The previous prime is 19776809761. The next prime is 19776809777. The reversal of 19776809771 is 17790867791.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19776809771 is a prime.

It is a super-2 number, since 2×19776809771² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19776809777) 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, 9888404885 + 9888404886.

It is an arithmetic number, because the mean of its divisors is an integer number (9888404886).

Almost surely, 2^19776809771 is an apocalyptic number.

19776809771 is a deficient number, since it is larger than the sum of its proper divisors (1).

19776809771 is an equidigital number, since it uses as much as digits as its factorization.

19776809771 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9335088, while the sum is 62.

The spelling of 19776809771 in words is "nineteen billion, seven hundred seventy-six million, eight hundred nine thousand, seven hundred seventy-one".