6781132781 has 2 divisors, whose sum is σ = 6781132782. Its totient is φ = 6781132780.

The previous prime is 6781132733. The next prime is 6781132801. The reversal of 6781132781 is 1872311876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6747143881 + 33988900 = 82141^2 + 5830^2 .

It is a cyclic number.

It is not a de Polignac number, because 6781132781 - 2³⁰ = 5707390957 is a prime.

It is a super-2 number, since 2×6781132781² = 91967523587105587922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6781132181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3390566390 + 3390566391.

It is an arithmetic number, because the mean of its divisors is an integer number (3390566391).

Almost surely, 2^6781132781 is an apocalyptic number.

It is an amenable number.

6781132781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6781132781 is an equidigital number, since it uses as much as digits as its factorization.

6781132781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 44.

The square root of 6781132781 is about 82347.6337304236. The cubic root of 6781132781 is about 1892.7826633653.

The spelling of 6781132781 in words is "six billion, seven hundred eighty-one million, one hundred thirty-two thousand, seven hundred eighty-one".