9981966569 has 2 divisors, whose sum is σ = 9981966570. Its totient is φ = 9981966568.

The previous prime is 9981966563. The next prime is 9981966587. The reversal of 9981966569 is 9656691899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9353210944 + 628755625 = 96712^2 + 25075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9981966569 is a prime.

It is a super-2 number, since 2×9981966569² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 9981966499 and 9981966508.

It is not a weakly prime, because it can be changed into another prime (9981966563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990983284 + 4990983285.

It is an arithmetic number, because the mean of its divisors is an integer number (4990983285).

Almost surely, 2^9981966569 is an apocalyptic number.

It is an amenable number.

9981966569 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981966569 is an equidigital number, since it uses as much as digits as its factorization.

9981966569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56687040, while the sum is 68.

The square root of 9981966569 is about 99909.7921577260. The cubic root of 9981966569 is about 2153.1388491266.

The spelling of 9981966569 in words is "nine billion, nine hundred eighty-one million, nine hundred sixty-six thousand, five hundred sixty-nine".