9993981 has 8 divisors (see below), whose sum is σ = 14026720. Its totient is φ = 6311952.

The previous prime is 9993967. The next prime is 9993989. The reversal of 9993981 is 1893999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9993981 - 2⁶ = 9993917 is a prime.

It is a super-2 number, since 2×9993981² = 199759312456722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9993981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9993989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87610 + ... + 87723.

It is an arithmetic number, because the mean of its divisors is an integer number (1753340).

Almost surely, 2^9993981 is an apocalyptic number.

It is an amenable number.

9993981 is a deficient number, since it is larger than the sum of its proper divisors (4032739).

9993981 is a wasteful number, since it uses less digits than its factorization.

9993981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175355.

The product of its digits is 157464, while the sum is 48.

The square root of 9993981 is about 3161.3258294583. The cubic root of 9993981 is about 215.4002351866.

The spelling of 9993981 in words is "nine million, nine hundred ninety-three thousand, nine hundred eighty-one".