8117783381 has 2 divisors, whose sum is σ = 8117783382. Its totient is φ = 8117783380.

The previous prime is 8117783371. The next prime is 8117783413. The reversal of 8117783381 is 1833877118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8106121156 + 11662225 = 90034^2 + 3415^2 .

It is a cyclic number.

It is not a de Polignac number, because 8117783381 - 2²⁶ = 8050674517 is a prime.

It is a super-2 number, since 2×8117783381² (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 (8117783321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4058891690 + 4058891691.

It is an arithmetic number, because the mean of its divisors is an integer number (4058891691).

Almost surely, 2^8117783381 is an apocalyptic number.

It is an amenable number.

8117783381 is a deficient number, since it is larger than the sum of its proper divisors (1).

8117783381 is an equidigital number, since it uses as much as digits as its factorization.

8117783381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 225792, while the sum is 47.

The square root of 8117783381 is about 90098.7423941089. The cubic root of 8117783381 is about 2009.7675020469.

The spelling of 8117783381 in words is "eight billion, one hundred seventeen million, seven hundred eighty-three thousand, three hundred eighty-one".