9930781 has 12 divisors (see below), whose sum is σ = 11604060. Its totient is φ = 8473920.

The previous prime is 9930773. The next prime is 9930797. The reversal of 9930781 is 1870399.

It can be written as a sum of positive squares in 2 ways, for example, as 2592100 + 7338681 = 1610^2 + 2709^2 .

It is not a de Polignac number, because 9930781 - 2³ = 9930773 is a prime.

It is a super-2 number, since 2×9930781² = 197240822539922, 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 9930781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9930581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18801 + ... + 19321.

It is an arithmetic number, because the mean of its divisors is an integer number (967005).

Almost surely, 2^9930781 is an apocalyptic number.

It is an amenable number.

9930781 is a deficient number, since it is larger than the sum of its proper divisors (1673279).

9930781 is a wasteful number, since it uses less digits than its factorization.

9930781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 924 (or 917 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 9930781 is about 3151.3141703105. The cubic root of 9930781 is about 214.9452249141.

The spelling of 9930781 in words is "nine million, nine hundred thirty thousand, seven hundred eighty-one".