191145231818 has 4 divisors (see below), whose sum is σ = 286717847730. Its totient is φ = 95572615908.

The previous prime is 191145231811. The next prime is 191145231857. The reversal of 191145231818 is 818132541191.

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

It can be written as a sum of positive squares in only one way, i.e., 178284084169 + 12861147649 = 422237^2 + 113407^2 .

It is a super-3 number, since 3×191145231818³ (a number of 35 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (191145231811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 47786307953 + ... + 47786307956.

Almost surely, 2^191145231818 is an apocalyptic number.

191145231818 is a deficient number, since it is larger than the sum of its proper divisors (95572615912).

191145231818 is an equidigital number, since it uses as much as digits as its factorization.

191145231818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95572615911.

The product of its digits is 69120, while the sum is 44.

The spelling of 191145231818 in words is "one hundred ninety-one billion, one hundred forty-five million, two hundred thirty-one thousand, eight hundred eighteen".