1918097189 has 4 divisors (see below), whose sum is σ = 1954287756. Its totient is φ = 1881906624.

The previous prime is 1918097183. The next prime is 1918097197. The reversal of 1918097189 is 9817908191.

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 1533348964 + 384748225 = 39158^2 + 19615^2 .

It is a cyclic number.

It is not a de Polignac number, because 1918097189 - 2⁸ = 1918096933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 36190513 = 1918097189 / (1 + 9 + 1 + 8 + 0 + 9 + 7 + 1 + 8 + 9).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1918097189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918097183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18095204 + ... + 18095309.

It is an arithmetic number, because the mean of its divisors is an integer number (488571939).

Almost surely, 2^1918097189 is an apocalyptic number.

It is an amenable number.

1918097189 is a deficient number, since it is larger than the sum of its proper divisors (36190567).

1918097189 is an equidigital number, since it uses as much as digits as its factorization.

1918097189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36190566.

The product of its (nonzero) digits is 326592, while the sum is 53.

The square root of 1918097189 is about 43796.0864575820. The cubic root of 1918097189 is about 1242.4822780448.

The spelling of 1918097189 in words is "one billion, nine hundred eighteen million, ninety-seven thousand, one hundred eighty-nine".