1999944928121 has 8 divisors (see below), whose sum is σ = 2287438417920. Its totient is φ = 1712898206208.

The previous prime is 1999944928073. The next prime is 1999944928127. The reversal of 1999944928121 is 1218294499991.

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

It is a de Polignac number, because none of the positive numbers 2^k-1999944928121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999944928127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111682376 + ... + 111700281.

It is an arithmetic number, because the mean of its divisors is an integer number (285929802240).

Almost surely, 2^{1999944928121} is an apocalyptic number.

It is an amenable number.

1999944928121 is a deficient number, since it is larger than the sum of its proper divisors (287493489799).

1999944928121 is a wasteful number, since it uses less digits than its factorization.

1999944928121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223383943.

The product of its digits is 30233088, while the sum is 68.

The spelling of 1999944928121 in words is "one trillion, nine hundred ninety-nine billion, nine hundred forty-four million, nine hundred twenty-eight thousand, one hundred twenty-one".