999979999999 has 4 divisors (see below), whose sum is σ = 999985163920. Its totient is φ = 999974836080.

The previous prime is 999979999987. The next prime is 999980000029. The reversal of 999979999999 is 999999979999.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 999979999999 - 2²³ = 999971611391 is a prime.

It is a Duffinian number.

999979999999 is a modest number, since divided by 999999 gives 999979 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999979999699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2279694 + ... + 2682715.

It is an arithmetic number, because the mean of its divisors is an integer number (249996290980).

Almost surely, 2^999979999999 is an apocalyptic number.

999979999999 is a deficient number, since it is larger than the sum of its proper divisors (5163921).

999979999999 is a wasteful number, since it uses less digits than its factorization.

999979999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5163920.

The product of its digits is 219667417263, while the sum is 106.

The spelling of 999979999999 in words is "nine hundred ninety-nine billion, nine hundred seventy-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".