10009981 has 2 divisors, whose sum is σ = 10009982. Its totient is φ = 10009980.

The previous prime is 10009963. The next prime is 10010023. The reversal of 10009981 is 18990001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6528025 + 3481956 = 2555^2 + 1866^2 .

It is a cyclic number.

It is not a de Polignac number, because 10009981 - 2⁹ = 10009469 is a prime.

It is a super-2 number, since 2×10009981² = 200399439240722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10009921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5004990 + 5004991.

It is an arithmetic number, because the mean of its divisors is an integer number (5004991).

Almost surely, 2^10009981 is an apocalyptic number.

It is an amenable number.

10009981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10009981 is an equidigital number, since it uses as much as digits as its factorization.

10009981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 10009981 is about 3163.8554012470. The cubic root of 10009981 is about 215.5151232113.

Adding to 10009981 its reverse (18990001), we get a palindrome (28999982).

The spelling of 10009981 in words is "ten million, nine thousand, nine hundred eighty-one".