999779708851 has 16 divisors (see below), whose sum is σ = 1246631931648. Its totient is φ = 778953290400.

The previous prime is 999779708833. The next prime is 999779708903. The reversal of 999779708851 is 158807977999.

It is a cyclic number.

It is not a de Polignac number, because 999779708851 - 2³¹ = 997632225203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999779708821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 165360 + ... + 1423693.

It is an arithmetic number, because the mean of its divisors is an integer number (77914495728).

Almost surely, 2^999779708851 is an apocalyptic number.

999779708851 is a deficient number, since it is larger than the sum of its proper divisors (246852222797).

999779708851 is a wasteful number, since it uses less digits than its factorization.

999779708851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597242.

The product of its (nonzero) digits is 720135360, while the sum is 79.

The spelling of 999779708851 in words is "nine hundred ninety-nine billion, seven hundred seventy-nine million, seven hundred eight thousand, eight hundred fifty-one".