9991304081 has 6 divisors (see below), whose sum is σ = 10982177346. Its totient is φ = 9083003600.

The previous prime is 9991304069. The next prime is 9991304093. The reversal of 9991304081 is 1804031999.

It is an interprime number because it is at equal distance from previous prime (9991304069) and next prime (9991304093).

It can be written as a sum of positive squares in only one way, i.e., 7811908225 + 2179395856 = 88385^2 + 46684^2 .

It is not a de Polignac number, because 9991304081 - 2¹⁸ = 9991041937 is a prime.

It is a super-2 number, since 2×9991304081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9991304041) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 41286260 + ... + 41286501.

It is an arithmetic number, because the mean of its divisors is an integer number (1830362891).

Almost surely, 2^9991304081 is an apocalyptic number.

It is an amenable number.

9991304081 is a deficient number, since it is larger than the sum of its proper divisors (990873265).

9991304081 is a wasteful number, since it uses less digits than its factorization.

9991304081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82572783 (or 82572772 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 9991304081 is about 99956.5109485120. The cubic root of 9991304081 is about 2153.8100159412.

The spelling of 9991304081 in words is "nine billion, nine hundred ninety-one million, three hundred four thousand, eighty-one".