18778212693 has 8 divisors (see below), whose sum is σ = 27819574400. Its totient is φ = 12518808444.

The previous prime is 18778212679. The next prime is 18778212697. The reversal of 18778212693 is 39621287781.

It is a happy number.

It is not a de Polignac number, because 18778212693 - 2²⁰ = 18777164117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18778212697) 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 in 7 ways as a sum of consecutive naturals, for example, 347744653 + ... + 347744706.

It is an arithmetic number, because the mean of its divisors is an integer number (3477446800).

Almost surely, 2^18778212693 is an apocalyptic number.

It is an amenable number.

18778212693 is a deficient number, since it is larger than the sum of its proper divisors (9041361707).

18778212693 is an equidigital number, since it uses as much as digits as its factorization.

18778212693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695489368 (or 695489362 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The spelling of 18778212693 in words is "eighteen billion, seven hundred seventy-eight million, two hundred twelve thousand, six hundred ninety-three".