800991101 has 4 divisors (see below), whose sum is σ = 803550492. Its totient is φ = 798431712.

The previous prime is 800991089. The next prime is 800991157. The reversal of 800991101 is 101199008.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 327972100 + 473019001 = 18110^2 + 21749^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-800991101 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (800991181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1279226 + ... + 1279851.

It is an arithmetic number, because the mean of its divisors is an integer number (200887623).

Almost surely, 2^800991101 is an apocalyptic number.

It is an amenable number.

800991101 is a deficient number, since it is larger than the sum of its proper divisors (2559391).

800991101 is a wasteful number, since it uses less digits than its factorization.

800991101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2559390.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 800991101 is about 28301.7861803809. The cubic root of 800991101 is about 928.7009654654.

The spelling of 800991101 in words is "eight hundred million, nine hundred ninety-one thousand, one hundred one".