9959999 has 4 divisors (see below), whose sum is σ = 11382864. Its totient is φ = 8537136.

The previous prime is 9959987. The next prime is 9960023. The reversal of 9959999 is 9999599.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9999599 = 127 ⋅78737.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9959999 is a prime.

It is a Duffinian number.

9959999 is a modest number, since divided by 9999 gives 995 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9959699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 711422 + ... + 711435.

It is an arithmetic number, because the mean of its divisors is an integer number (2845716).

Almost surely, 2^9959999 is an apocalyptic number.

9959999 is a deficient number, since it is larger than the sum of its proper divisors (1422865).

9959999 is a wasteful number, since it uses less digits than its factorization.

9959999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422864.

The product of its digits is 2657205, while the sum is 59.

The square root of 9959999 is about 3155.9466091808. The cubic root of 9959999 is about 215.1558199798.

The spelling of 9959999 in words is "nine million, nine hundred fifty-nine thousand, nine hundred ninety-nine".