9999681 has 8 divisors (see below), whose sum is σ = 14034720. Its totient is φ = 6315552.

The previous prime is 9999677. The next prime is 9999713. The reversal of 9999681 is 1869999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9999681 - 2² = 9999677 is a prime.

It is a super-2 number, since 2×9999681² = 199987240203522, which contains 22 as substring.

9999681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (9999601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87660 + ... + 87773.

It is an arithmetic number, because the mean of its divisors is an integer number (1754340).

Almost surely, 2^9999681 is an apocalyptic number.

It is an amenable number.

9999681 is a deficient number, since it is larger than the sum of its proper divisors (4035039).

9999681 is a wasteful number, since it uses less digits than its factorization.

9999681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175455.

The product of its digits is 314928, while the sum is 51.

The square root of 9999681 is about 3162.2272214374. The cubic root of 9999681 is about 215.4411780966.

The spelling of 9999681 in words is "nine million, nine hundred ninety-nine thousand, six hundred eighty-one".