7649686661 has 2 divisors, whose sum is σ = 7649686662. Its totient is φ = 7649686660.

The previous prime is 7649686651. The next prime is 7649686687. The reversal of 7649686661 is 1666869467.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5430805636 + 2218881025 = 73694^2 + 47105^2 .

It is an emirp because it is prime and its reverse (1666869467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7649686661 - 2¹⁴ = 7649670277 is a prime.

It is a super-2 number, since 2×7649686661² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7649686661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7649686651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3824843330 + 3824843331.

It is an arithmetic number, because the mean of its divisors is an integer number (3824843331).

Almost surely, 2^7649686661 is an apocalyptic number.

It is an amenable number.

7649686661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7649686661 is an equidigital number, since it uses as much as digits as its factorization.

7649686661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 59.

The square root of 7649686661 is about 87462.4871644981. The cubic root of 7649686661 is about 1970.3704338316.

The spelling of 7649686661 in words is "seven billion, six hundred forty-nine million, six hundred eighty-six thousand, six hundred sixty-one".