7663691561 has 2 divisors, whose sum is σ = 7663691562. Its totient is φ = 7663691560.

The previous prime is 7663691557. The next prime is 7663691569. The reversal of 7663691561 is 1651963667.

It is a happy number.

7663691561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4322273536 + 3341418025 = 65744^2 + 57805^2 .

It is an emirp because it is prime and its reverse (1651963667) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7663691561 - 2² = 7663691557 is a prime.

It is not a weakly prime, because it can be changed into another prime (7663691569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3831845780 + 3831845781.

It is an arithmetic number, because the mean of its divisors is an integer number (3831845781).

Almost surely, 2^7663691561 is an apocalyptic number.

It is an amenable number.

7663691561 is a deficient number, since it is larger than the sum of its proper divisors (1).

7663691561 is an equidigital number, since it uses as much as digits as its factorization.

7663691561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1224720, while the sum is 50.

The square root of 7663691561 is about 87542.5128780297. The cubic root of 7663691561 is about 1971.5721396087.

The spelling of 7663691561 in words is "seven billion, six hundred sixty-three million, six hundred ninety-one thousand, five hundred sixty-one".