11809556771 has 2 divisors, whose sum is σ = 11809556772. Its totient is φ = 11809556770.

The previous prime is 11809556741. The next prime is 11809556779. The reversal of 11809556771 is 17765590811.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11809556771 is a prime.

It is a super-2 number, since 2×11809556771² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11809556779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5904778385 + 5904778386.

It is an arithmetic number, because the mean of its divisors is an integer number (5904778386).

Almost surely, 2^11809556771 is an apocalyptic number.

11809556771 is a deficient number, since it is larger than the sum of its proper divisors (1).

11809556771 is an equidigital number, since it uses as much as digits as its factorization.

11809556771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 529200, while the sum is 50.

The spelling of 11809556771 in words is "eleven billion, eight hundred nine million, five hundred fifty-six thousand, seven hundred seventy-one".