781797544856 has 8 divisors (see below), whose sum is σ = 1465870396620. Its totient is φ = 390898772424.

The previous prime is 781797544817. The next prime is 781797544883. The reversal of 781797544856 is 658445797187.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×781797544856² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 781797544856.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 48862346546 + ... + 48862346561.

Almost surely, 2^781797544856 is an apocalyptic number.

It is an amenable number.

781797544856 is a deficient number, since it is larger than the sum of its proper divisors (684072851764).

781797544856 is a wasteful number, since it uses less digits than its factorization.

781797544856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97724693113 (or 97724693109 counting only the distinct ones).

The product of its digits is 474163200, while the sum is 71.

The spelling of 781797544856 in words is "seven hundred eighty-one billion, seven hundred ninety-seven million, five hundred forty-four thousand, eight hundred fifty-six".