18219639793 has 2 divisors, whose sum is σ = 18219639794. Its totient is φ = 18219639792.

The previous prime is 18219639791. The next prime is 18219639829. The reversal of 18219639793 is 39793691281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12304799329 + 5914840464 = 110927^2 + 76908^2 .

It is a cyclic number.

It is not a de Polignac number, because 18219639793 - 2¹ = 18219639791 is a prime.

Together with 18219639791, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18219639791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9109819896 + 9109819897.

It is an arithmetic number, because the mean of its divisors is an integer number (9109819897).

Almost surely, 2^18219639793 is an apocalyptic number.

It is an amenable number.

18219639793 is a deficient number, since it is larger than the sum of its proper divisors (1).

18219639793 is an equidigital number, since it uses as much as digits as its factorization.

18219639793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4408992, while the sum is 58.

The spelling of 18219639793 in words is "eighteen billion, two hundred nineteen million, six hundred thirty-nine thousand, seven hundred ninety-three".