7886505661 has 2 divisors, whose sum is σ = 7886505662. Its totient is φ = 7886505660.

The previous prime is 7886505619. The next prime is 7886505749. The reversal of 7886505661 is 1665056887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7886505636 + 25 = 88806^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 7886505661 - 2⁷ = 7886505533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7886505599 and 7886505608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7886505761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3943252830 + 3943252831.

It is an arithmetic number, because the mean of its divisors is an integer number (3943252831).

Almost surely, 2^7886505661 is an apocalyptic number.

It is an amenable number.

7886505661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7886505661 is an equidigital number, since it uses as much as digits as its factorization.

7886505661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2419200, while the sum is 52.

The square root of 7886505661 is about 88806.0001407563. Note that the first 3 decimals coincide. The cubic root of 7886505661 is about 1990.4970569679.

The spelling of 7886505661 in words is "seven billion, eight hundred eighty-six million, five hundred five thousand, six hundred sixty-one".