9979999 has 8 divisors (see below), whose sum is σ = 10657152. Its totient is φ = 9323160.

The previous prime is 9979993. The next prime is 9980017. The reversal of 9979999 is 9999799.

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

It is a cyclic number.

It is not a de Polignac number, because 9979999 - 2⁵ = 9979967 is a prime.

It is a Duffinian number.

9979999 is a modest number, since divided by 9999 gives 997 as remainder.

9979999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979993) by changing a digit.

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, 4057 + ... + 6034.

It is an arithmetic number, because the mean of its divisors is an integer number (1332144).

Almost surely, 2^9979999 is an apocalyptic number.

9979999 is a deficient number, since it is larger than the sum of its proper divisors (677153).

9979999 is a wasteful number, since it uses less digits than its factorization.

9979999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10157.

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

The square root of 9979999 is about 3159.1136415140. The cubic root of 9979999 is about 215.2997369736.

The spelling of 9979999 in words is "nine million, nine hundred seventy-nine thousand, nine hundred ninety-nine".