781241872320 has 2688 divisors, whose sum is σ = 3767152435200. Its totient is φ = 150493593600.

The previous prime is 781241872291. The next prime is 781241872373. The reversal of 781241872320 is 23278142187.

781241872320 is a `hidden beast` number, since 7 + 8 + 1 + 241 + 87 + 2 + 320 = 666.

It is a super-2 number, since 2×781241872320² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 3241667400 + ... + 3241667640.

It is an arithmetic number, because the mean of its divisors is an integer number (1401470400).

Almost surely, 2^781241872320 is an apocalyptic number.

781241872320 is a gapful number since it is divisible by the number (70) 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 781241872320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1883576217600).

781241872320 is an abundant number, since it is smaller than the sum of its proper divisors (2985910562880).

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

781241872320 is a wasteful number, since it uses less digits than its factorization.

781241872320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

It can be divided in two parts, 781241 and 872320, that added together give a palindrome (1653561).

The spelling of 781241872320 in words is "seven hundred eighty-one billion, two hundred forty-one million, eight hundred seventy-two thousand, three hundred twenty".