9669815581 has 2 divisors, whose sum is σ = 9669815582. Its totient is φ = 9669815580.

The previous prime is 9669815567. The next prime is 9669815599. The reversal of 9669815581 is 1855189669.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7627227556 + 2042588025 = 87334^2 + 45195^2 .

It is an emirp because it is prime and its reverse (1855189669) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9669815581 - 2¹⁵ = 9669782813 is a prime.

It is a super-2 number, since 2×9669815581² (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 (9669815381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4834907790 + 4834907791.

It is an arithmetic number, because the mean of its divisors is an integer number (4834907791).

Almost surely, 2^9669815581 is an apocalyptic number.

It is an amenable number.

9669815581 is a deficient number, since it is larger than the sum of its proper divisors (1).

9669815581 is an equidigital number, since it uses as much as digits as its factorization.

9669815581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4665600, while the sum is 58.

The square root of 9669815581 is about 98335.2204502537. The cubic root of 9669815581 is about 2130.4567911701.

The spelling of 9669815581 in words is "nine billion, six hundred sixty-nine million, eight hundred fifteen thousand, five hundred eighty-one".