9963581 has 16 divisors (see below), whose sum is σ = 11246400. Its totient is φ = 8771328.

The previous prime is 9963571. The next prime is 9963587. The reversal of 9963581 is 1853699.

9963581 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9963581 is a prime.

It is a super-2 number, since 2×9963581² = 198545892687122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9963587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35066 + ... + 35348.

It is an arithmetic number, because the mean of its divisors is an integer number (702900).

Almost surely, 2^9963581 is an apocalyptic number.

It is an amenable number.

9963581 is a deficient number, since it is larger than the sum of its proper divisors (1282819).

9963581 is a wasteful number, since it uses less digits than its factorization.

9963581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428.

The product of its digits is 58320, while the sum is 41.

The square root of 9963581 is about 3156.5140582611. The cubic root of 9963581 is about 215.1816096670.

It can be divided in two parts, 9963 and 581, that multiplied together give a triangular number (5788503 = T₃₄₀₂).

The spelling of 9963581 in words is "nine million, nine hundred sixty-three thousand, five hundred eighty-one".