11788131781 has 2 divisors, whose sum is σ = 11788131782. Its totient is φ = 11788131780.

The previous prime is 11788131749. The next prime is 11788131811. The reversal of 11788131781 is 18713188711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9636563556 + 2151568225 = 98166^2 + 46385^2 .

It is a cyclic number.

It is not a de Polignac number, because 11788131781 - 2⁵ = 11788131749 is a prime.

It is a super-2 number, since 2×11788131781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11788131881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5894065890 + 5894065891.

It is an arithmetic number, because the mean of its divisors is an integer number (5894065891).

Almost surely, 2^11788131781 is an apocalyptic number.

It is an amenable number.

11788131781 is a deficient number, since it is larger than the sum of its proper divisors (1).

11788131781 is an equidigital number, since it uses as much as digits as its factorization.

11788131781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 46.

The spelling of 11788131781 in words is "eleven billion, seven hundred eighty-eight million, one hundred thirty-one thousand, seven hundred eighty-one".