991121121101121 has 16 divisors (see below), whose sum is σ = 1407814050049344. Its totient is φ = 618064704889344.

The previous prime is 991121121101119. The next prime is 991121121101129. The reversal of 991121121101121 is 121101121121199.

It is not a de Polignac number, because 991121121101121 - 2¹ = 991121121101119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991121121101129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59612713996 + ... + 59612730621.

It is an arithmetic number, because the mean of its divisors is an integer number (87988378128084).

Almost surely, 2^{991121121101121} is an apocalyptic number.

It is an amenable number.

991121121101121 is a deficient number, since it is larger than the sum of its proper divisors (416692928948223).

991121121101121 is a wasteful number, since it uses less digits than its factorization.

991121121101121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119225444800.

The product of its (nonzero) digits is 648, while the sum is 33.

The spelling of 991121121101121 in words is "nine hundred ninety-one trillion, one hundred twenty-one billion, one hundred twenty-one million, one hundred one thousand, one hundred twenty-one".