9775981 has 4 divisors (see below), whose sum is σ = 9818172. Its totient is φ = 9733792.

The previous prime is 9775949. The next prime is 9775993. The reversal of 9775981 is 1895779.

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 3575881 + 6200100 = 1891^2 + 2490^2 .

It is a cyclic number.

It is not a de Polignac number, because 9775981 - 2⁵ = 9775949 is a prime.

It is a super-2 number, since 2×9775981² = 191139609024722, 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 (9772981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20746 + ... + 21211.

It is an arithmetic number, because the mean of its divisors is an integer number (2454543).

Almost surely, 2^9775981 is an apocalyptic number.

It is an amenable number.

9775981 is a deficient number, since it is larger than the sum of its proper divisors (42191).

9775981 is a wasteful number, since it uses less digits than its factorization.

9775981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42190.

The product of its digits is 158760, while the sum is 46.

The square root of 9775981 is about 3126.6565209501. The cubic root of 9775981 is about 213.8225229555.

The spelling of 9775981 in words is "nine million, seven hundred seventy-five thousand, nine hundred eighty-one".