9999645 has 8 divisors (see below), whose sum is σ = 15999456. Its totient is φ = 5333136.

The previous prime is 9999637. The next prime is 9999653. The reversal of 9999645 is 5469999.

It is an interprime number because it is at equal distance from previous prime (9999637) and next prime (9999653).

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

It is not a de Polignac number, because 9999645 - 2³ = 9999637 is a prime.

9999645 is a lucky number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 333307 + ... + 333336.

It is an arithmetic number, because the mean of its divisors is an integer number (1999932).

Almost surely, 2^9999645 is an apocalyptic number.

It is an amenable number.

9999645 is a deficient number, since it is larger than the sum of its proper divisors (5999811).

9999645 is a wasteful number, since it uses less digits than its factorization.

9999645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666651.

The product of its digits is 787320, while the sum is 51.

The square root of 9999645 is about 3162.2215292417. The cubic root of 9999645 is about 215.4409195586.

The spelling of 9999645 in words is "nine million, nine hundred ninety-nine thousand, six hundred forty-five".