7668158581 has 2 divisors, whose sum is σ = 7668158582. Its totient is φ = 7668158580.

The previous prime is 7668158513. The next prime is 7668158587. The reversal of 7668158581 is 1858518667.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7364214225 + 303944356 = 85815^2 + 17434^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7668158581 is a prime.

It is a super-2 number, since 2×7668158581² (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 (7668158587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3834079290 + 3834079291.

It is an arithmetic number, because the mean of its divisors is an integer number (3834079291).

Almost surely, 2^7668158581 is an apocalyptic number.

It is an amenable number.

7668158581 is a deficient number, since it is larger than the sum of its proper divisors (1).

7668158581 is an equidigital number, since it uses as much as digits as its factorization.

7668158581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3225600, while the sum is 55.

The square root of 7668158581 is about 87568.0225938670. The cubic root of 7668158581 is about 1971.9551291688.

The spelling of 7668158581 in words is "seven billion, six hundred sixty-eight million, one hundred fifty-eight thousand, five hundred eighty-one".