1808958391189 has 2 divisors, whose sum is σ = 1808958391190. Its totient is φ = 1808958391188.

The previous prime is 1808958391171. The next prime is 1808958391213. The reversal of 1808958391189 is 9811938598081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1804038491025 + 4919900164 = 1343145^2 + 70142^2 .

It is a cyclic number.

It is not a de Polignac number, because 1808958391189 - 2⁷ = 1808958391061 is a prime.

It is a super-2 number, since 2×1808958391189² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1808958391489) 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 as a sum of consecutive naturals, namely, 904479195594 + 904479195595.

It is an arithmetic number, because the mean of its divisors is an integer number (904479195595).

Almost surely, 2^{1808958391189} is an apocalyptic number.

It is an amenable number.

1808958391189 is a deficient number, since it is larger than the sum of its proper divisors (1).

1808958391189 is an equidigital number, since it uses as much as digits as its factorization.

1808958391189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44789760, while the sum is 70.

The spelling of 1808958391189 in words is "one trillion, eight hundred eight billion, nine hundred fifty-eight million, three hundred ninety-one thousand, one hundred eighty-nine".