999956798121 has 8 divisors (see below), whose sum is σ = 1391244240960. Its totient is φ = 637653610352.

The previous prime is 999956798119. The next prime is 999956798143. The reversal of 999956798121 is 121897659999.

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 999956798121 - 2¹ = 999956798119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999956798171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7246063686 + ... + 7246063823.

It is an arithmetic number, because the mean of its divisors is an integer number (173905530120).

Almost surely, 2^999956798121 is an apocalyptic number.

It is an amenable number.

999956798121 is a deficient number, since it is larger than the sum of its proper divisors (391287442839).

999956798121 is a wasteful number, since it uses less digits than its factorization.

999956798121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14492127535.

The product of its digits is 198404640, while the sum is 75.

The spelling of 999956798121 in words is "nine hundred ninety-nine billion, nine hundred fifty-six million, seven hundred ninety-eight thousand, one hundred twenty-one".