7668006781 has 2 divisors, whose sum is σ = 7668006782. Its totient is φ = 7668006780.

The previous prime is 7668006779. The next prime is 7668006809. The reversal of 7668006781 is 1876008667.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7113404281 + 554602500 = 84341^2 + 23550^2 .

It is a cyclic number.

It is not a de Polignac number, because 7668006781 - 2¹ = 7668006779 is a prime.

It is a super-2 number, since 2×7668006781² (a number of 21 digits) contains 22 as substring.

Together with 7668006779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7668006721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3834003390 + 3834003391.

It is an arithmetic number, because the mean of its divisors is an integer number (3834003391).

Almost surely, 2^7668006781 is an apocalyptic number.

It is an amenable number.

7668006781 is a deficient number, since it is larger than the sum of its proper divisors (1).

7668006781 is an equidigital number, since it uses as much as digits as its factorization.

7668006781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 49.

The square root of 7668006781 is about 87567.1558348220. The cubic root of 7668006781 is about 1971.9421167113.

The spelling of 7668006781 in words is "seven billion, six hundred sixty-eight million, six thousand, seven hundred eighty-one".