9999999997 has 4 divisors (see below), whose sum is σ = 10769230780. Its totient is φ = 9230769216.

The previous prime is 9999999967. The next prime is 10000000019. The reversal of 9999999997 is 7999999999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7999999999 = 1999 ⋅4002001.

It can be written as a sum of positive squares in 2 ways, for example, as 4460770521 + 5539229476 = 66789^2 + 74426^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999999997 - 2²³ = 9991611389 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999999967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 384615372 + ... + 384615397.

It is an arithmetic number, because the mean of its divisors is an integer number (2692307695).

Almost surely, 2^9999999997 is an apocalyptic number.

It is an amenable number.

9999999997 is a deficient number, since it is larger than the sum of its proper divisors (769230783).

9999999997 is a wasteful number, since it uses less digits than its factorization.

9999999997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769230782.

The product of its digits is 2711943423, while the sum is 88.

The square root of 9999999997 is about 99999.9999850000. Note that the first 4 decimals coincide. The cubic root of 9999999997 is about 2154.4346898164.

The spelling of 9999999997 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-seven".