781018020008 has 16 divisors (see below), whose sum is σ = 1465053084180. Its totient is φ = 390337197568.

The previous prime is 781018019993. The next prime is 781018020043. The reversal of 781018020008 is 800020810187.

It can be written as a sum of positive squares in 2 ways, for example, as 773594129764 + 7423890244 = 879542^2 + 86162^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 781018020008.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 21457235 + ... + 21493602.

Almost surely, 2^781018020008 is an apocalyptic number.

It is an amenable number.

781018020008 is a deficient number, since it is larger than the sum of its proper divisors (684035064172).

781018020008 is a wasteful number, since it uses less digits than its factorization.

781018020008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42953116 (or 42953112 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 35.

The spelling of 781018020008 in words is "seven hundred eighty-one billion, eighteen million, twenty thousand, eight".