781681812912 has 2160 divisors, whose sum is σ = 3338197175040. Its totient is φ = 171824716800.

The previous prime is 781681812907. The next prime is 781681812997. The reversal of 781681812912 is 219218186187.

It is a super-2 number, since 2×781681812912² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 25215542337 + ... + 25215542367.

Almost surely, 2^781681812912 is an apocalyptic number.

781681812912 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781681812912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1669098587520).

781681812912 is an abundant number, since it is smaller than the sum of its proper divisors (2556515362128).

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

781681812912 is a wasteful number, since it uses less digits than its factorization.

781681812912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 86 counting only the distinct ones).

The product of its digits is 774144, while the sum is 54.

The spelling of 781681812912 in words is "seven hundred eighty-one billion, six hundred eighty-one million, eight hundred twelve thousand, nine hundred twelve".