1781738465856 has 56 divisors (see below), whose sum is σ = 4714902700224. Its totient is φ = 593822154240.

The previous prime is 1781738465831. The next prime is 1781738465861. The reversal of 1781738465856 is 6585648371871.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 558501 + ... + 1968603.

Almost surely, 2^{1781738465856} is an apocalyptic number.

1781738465856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1781738465856 is an abundant number, since it is smaller than the sum of its proper divisors (2933164234368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1781738465856 is a wasteful number, since it uses less digits than its factorization.

1781738465856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1416699 (or 1416689 counting only the distinct ones).

The product of its digits is 270950400, while the sum is 69.

The spelling of 1781738465856 in words is "one trillion, seven hundred eighty-one billion, seven hundred thirty-eight million, four hundred sixty-five thousand, eight hundred fifty-six".