9943581 has 4 divisors (see below), whose sum is σ = 13258112. Its totient is φ = 6629052.

The previous prime is 9943579. The next prime is 9943663. The reversal of 9943581 is 1853499.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 9943581 - 2¹ = 9943579 is a prime.

It is a super-2 number, since 2×9943581² = 197749606207122, which contains 22 as substring.

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 (9943481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1657261 + ... + 1657266.

It is an arithmetic number, because the mean of its divisors is an integer number (3314528).

Almost surely, 2^9943581 is an apocalyptic number.

It is an amenable number.

9943581 is a deficient number, since it is larger than the sum of its proper divisors (3314531).

9943581 is a wasteful number, since it uses less digits than its factorization.

9943581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3314530.

The product of its digits is 38880, while the sum is 39.

The square root of 9943581 is about 3153.3444150616. The cubic root of 9943581 is about 215.0375344601.

The spelling of 9943581 in words is "nine million, nine hundred forty-three thousand, five hundred eighty-one".