18218778657802 has 8 divisors (see below), whose sum is σ = 27341376387300. Its totient is φ = 9104986528704.

The previous prime is 18218778657767. The next prime is 18218778657851. The reversal of 18218778657802 is 20875687781281.

It can be written as a sum of positive squares in 2 ways, for example, as 14521045801201 + 3697732856601 = 3810649^2 + 1922949^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2201394927 + ... + 2201403202.

Almost surely, 2^{18218778657802} is an apocalyptic number.

18218778657802 is a deficient number, since it is larger than the sum of its proper divisors (9122597729498).

18218778657802 is a wasteful number, since it uses less digits than its factorization.

18218778657802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4402800200.

The product of its (nonzero) digits is 168591360, while the sum is 70.

The spelling of 18218778657802 in words is "eighteen trillion, two hundred eighteen billion, seven hundred seventy-eight million, six hundred fifty-seven thousand, eight hundred two".