1208081991 has 8 divisors (see below), whose sum is σ = 1611042160. Its totient is φ = 805254912.

The previous prime is 1208081929. The next prime is 1208082011. The reversal of 1208081991 is 1991808021.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1208081991 - 2¹⁰ = 1208080967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1208081911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9706 + ... + 50103.

It is an arithmetic number, because the mean of its divisors is an integer number (201380270).

Almost surely, 2^1208081991 is an apocalyptic number.

1208081991 is a deficient number, since it is larger than the sum of its proper divisors (402960169).

1208081991 is an equidigital number, since it uses as much as digits as its factorization.

1208081991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66545.

The product of its (nonzero) digits is 10368, while the sum is 39.

The square root of 1208081991 is about 34757.4738869211. The cubic root of 1208081991 is about 1065.0388991501.

The spelling of 1208081991 in words is "one billion, two hundred eight million, eighty-one thousand, nine hundred ninety-one".