991101099121 has 16 divisors (see below), whose sum is σ = 1141506979200. Its totient is φ = 842912403840.

The previous prime is 991101099119. The next prime is 991101099133. The reversal of 991101099121 is 121990101199.

991101099121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 991101099121 - 2¹ = 991101099119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991101091121) 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, 470226 + ... + 1484356.

It is an arithmetic number, because the mean of its divisors is an integer number (71344186200).

Almost surely, 2^991101099121 is an apocalyptic number.

It is an amenable number.

991101099121 is a deficient number, since it is larger than the sum of its proper divisors (150405880079).

991101099121 is a wasteful number, since it uses less digits than its factorization.

991101099121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015224.

The product of its (nonzero) digits is 13122, while the sum is 43.

The spelling of 991101099121 in words is "nine hundred ninety-one billion, one hundred one million, ninety-nine thousand, one hundred twenty-one".