9656945581 has 2 divisors, whose sum is σ = 9656945582. Its totient is φ = 9656945580.

The previous prime is 9656945549. The next prime is 9656945587. The reversal of 9656945581 is 1855496569.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5410338025 + 4246607556 = 73555^2 + 65166^2 .

It is a cyclic number.

It is not a de Polignac number, because 9656945581 - 2⁵ = 9656945549 is a prime.

It is a super-2 number, since 2×9656945581² (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 (9656945587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4828472790 + 4828472791.

It is an arithmetic number, because the mean of its divisors is an integer number (4828472791).

Almost surely, 2^9656945581 is an apocalyptic number.

It is an amenable number.

9656945581 is a deficient number, since it is larger than the sum of its proper divisors (1).

9656945581 is an equidigital number, since it uses as much as digits as its factorization.

9656945581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664000, while the sum is 58.

The square root of 9656945581 is about 98269.7592395545. The cubic root of 9656945581 is about 2129.5111973937.

The spelling of 9656945581 in words is "nine billion, six hundred fifty-six million, nine hundred forty-five thousand, five hundred eighty-one".