991000201121 has 8 divisors (see below), whose sum is σ = 1133487247680. Its totient is φ = 848742051888.

The previous prime is 991000201069. The next prime is 991000201129. The reversal of 991000201121 is 121102000199.

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 991000201121 - 2³⁴ = 973820331937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991000201129) 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, 57215051 + ... + 57232368.

It is an arithmetic number, because the mean of its divisors is an integer number (141685905960).

Almost surely, 2^991000201121 is an apocalyptic number.

It is an amenable number.

991000201121 is a deficient number, since it is larger than the sum of its proper divisors (142487046559).

991000201121 is a wasteful number, since it uses less digits than its factorization.

991000201121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114448663.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 991000201121 in words is "nine hundred ninety-one billion, two hundred one thousand, one hundred twenty-one".