18949491289 has 2 divisors, whose sum is σ = 18949491290. Its totient is φ = 18949491288.

The previous prime is 18949491283. The next prime is 18949491313. The reversal of 18949491289 is 98219494981.

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., 11009255625 + 7940235664 = 104925^2 + 89108^2 .

It is a cyclic number.

It is not a de Polignac number, because 18949491289 - 2¹⁷ = 18949360217 is a prime.

It is a super-3 number, since 3×18949491289³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 18949491289.

It is not a weakly prime, because it can be changed into another prime (18949491283) 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 as a sum of consecutive naturals, namely, 9474745644 + 9474745645.

It is an arithmetic number, because the mean of its divisors is an integer number (9474745645).

Almost surely, 2^18949491289 is an apocalyptic number.

It is an amenable number.

18949491289 is a deficient number, since it is larger than the sum of its proper divisors (1).

18949491289 is an equidigital number, since it uses as much as digits as its factorization.

18949491289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13436928, while the sum is 64.

The spelling of 18949491289 in words is "eighteen billion, nine hundred forty-nine million, four hundred ninety-one thousand, two hundred eighty-nine".