9947981 has 4 divisors (see below), whose sum is σ = 10020732. Its totient is φ = 9875232.

The previous prime is 9947969. The next prime is 9947999. The reversal of 9947981 is 1897499.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6916900 + 3031081 = 2630^2 + 1741^2 .

It is a cyclic number.

It is not a de Polignac number, because 9947981 - 2¹⁰ = 9946957 is a prime.

It is a super-2 number, since 2×9947981² = 197924651952722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9947281) 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, 36170 + ... + 36443.

It is an arithmetic number, because the mean of its divisors is an integer number (2505183).

Almost surely, 2^9947981 is an apocalyptic number.

It is an amenable number.

9947981 is a deficient number, since it is larger than the sum of its proper divisors (72751).

9947981 is a wasteful number, since it uses less digits than its factorization.

9947981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72750.

The product of its digits is 163296, while the sum is 47.

The square root of 9947981 is about 3154.0420098661. The cubic root of 9947981 is about 215.0692475698.

The spelling of 9947981 in words is "nine million, nine hundred forty-seven thousand, nine hundred eighty-one".