9999997 has 4 divisors (see below), whose sum is σ = 11428576. Its totient is φ = 8571420.

The previous prime is 9999991. The next prime is 10000019. The reversal of 9999997 is 7999999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9999997 is a prime.

It is a Duffinian number.

9999997 is a lucky 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 (9999991) 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, 714279 + ... + 714292.

It is an arithmetic number, because the mean of its divisors is an integer number (2857144).

Almost surely, 2^9999997 is an apocalyptic number.

It is an amenable number.

9999997 is a deficient number, since it is larger than the sum of its proper divisors (1428579).

9999997 is a wasteful number, since it uses less digits than its factorization.

9999997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1428578.

The product of its digits is 3720087, while the sum is 61.

The square root of 9999997 is about 3162.2771858267. The cubic root of 9999997 is about 215.4434474588.

The spelling of 9999997 in words is "nine million, nine hundred ninety-nine thousand, nine hundred ninety-seven".