991121100011 has 16 divisors (see below), whose sum is σ = 1147223193600. Its totient is φ = 838650634848.

The previous prime is 991121099993. The next prime is 991121100097. The reversal of 991121100011 is 110001121199.

It is a cyclic number.

It is not a de Polignac number, because 991121100011 - 2³⁰ = 990047358187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991121100311) 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, 3576506 + ... + 3843648.

It is an arithmetic number, because the mean of its divisors is an integer number (71701449600).

Almost surely, 2^991121100011 is an apocalyptic number.

991121100011 is a deficient number, since it is larger than the sum of its proper divisors (156102093589).

991121100011 is a wasteful number, since it uses less digits than its factorization.

991121100011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273938.

The product of its (nonzero) digits is 162, while the sum is 26.

The spelling of 991121100011 in words is "nine hundred ninety-one billion, one hundred twenty-one million, one hundred thousand, eleven".