9865981 has 4 divisors (see below), whose sum is σ = 9879772. Its totient is φ = 9852192.

The previous prime is 9865979. The next prime is 9865993. The reversal of 9865981 is 1895689.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1895689 = 821 ⋅2309.

It can be written as a sum of positive squares in 2 ways, for example, as 6125625 + 3740356 = 2475^2 + 1934^2 .

It is a cyclic number.

It is not a de Polignac number, because 9865981 - 2¹ = 9865979 is a prime.

It is a super-2 number, since 2×9865981² = 194675162184722, 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 (9865931) 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, 5760 + ... + 7273.

It is an arithmetic number, because the mean of its divisors is an integer number (2469943).

Almost surely, 2^9865981 is an apocalyptic number.

It is an amenable number.

9865981 is a deficient number, since it is larger than the sum of its proper divisors (13791).

9865981 is a wasteful number, since it uses less digits than its factorization.

9865981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13790.

The product of its digits is 155520, while the sum is 46.

The square root of 9865981 is about 3141.0159184570. The cubic root of 9865981 is about 214.4766865373.

The spelling of 9865981 in words is "nine million, eight hundred sixty-five thousand, nine hundred eighty-one".