9939999 has 16 divisors (see below), whose sum is σ = 13676544. Its totient is φ = 6417600.

The previous prime is 9939971. The next prime is 9940001. The reversal of 9939999 is 9999399.

It is not a de Polignac number, because 9939999 - 2¹³ = 9931807 is a prime.

9939999 is a modest number, since divided by 9999 gives 993 as remainder.

9939999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9939949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25762 + ... + 26144.

It is an arithmetic number, because the mean of its divisors is an integer number (854784).

Almost surely, 2^9939999 is an apocalyptic number.

9939999 is a deficient number, since it is larger than the sum of its proper divisors (3736545).

9939999 is a wasteful number, since it uses less digits than its factorization.

9939999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638.

The product of its digits is 1594323, while the sum is 57.

The square root of 9939999 is about 3152.7763954965. The cubic root of 9939999 is about 215.0117101969.

The spelling of 9939999 in words is "nine million, nine hundred thirty-nine thousand, nine hundred ninety-nine".