1318919991 has 8 divisors (see below), whose sum is σ = 1784807424. Its totient is φ = 866156280.

The previous prime is 1318919963. The next prime is 1318920007. The reversal of 1318919991 is 1999198131.

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

It is not a de Polignac number, because 1318919991 - 2⁷ = 1318919863 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1318911991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3280695 + ... + 3281096.

It is an arithmetic number, because the mean of its divisors is an integer number (223100928).

Almost surely, 2^1318919991 is an apocalyptic number.

1318919991 is a deficient number, since it is larger than the sum of its proper divisors (465887433).

1318919991 is an equidigital number, since it uses as much as digits as its factorization.

1318919991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6561861.

The product of its digits is 157464, while the sum is 51.

The square root of 1318919991 is about 36316.9380730259. The cubic root of 1318919991 is about 1096.6620550963.

The spelling of 1318919991 in words is "one billion, three hundred eighteen million, nine hundred nineteen thousand, nine hundred ninety-one".