18643896228191 has 64 divisors (see below), whose sum is σ = 21869896237056. Its totient is φ = 15767382758400.

The previous prime is 18643896228149. The next prime is 18643896228229. The reversal of 18643896228191 is 19182269834681.

It is not a de Polignac number, because 18643896228191 - 2¹⁴ = 18643896211807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18643896228131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 71144195 + ... + 71405771.

It is an arithmetic number, because the mean of its divisors is an integer number (341717128704).

Almost surely, 2^{18643896228191} is an apocalyptic number.

18643896228191 is a deficient number, since it is larger than the sum of its proper divisors (3226000008865).

18643896228191 is a wasteful number, since it uses less digits than its factorization.

18643896228191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261792.

The product of its digits is 71663616, while the sum is 68.

The spelling of 18643896228191 in words is "eighteen trillion, six hundred forty-three billion, eight hundred ninety-six million, two hundred twenty-eight thousand, one hundred ninety-one".