781221130560 has 504 divisors, whose sum is σ = 2916371412864. Its totient is φ = 191858135040.

The previous prime is 781221130559. The next prime is 781221130577. The reversal of 781221130560 is 65031122187.

781221130560 is a `hidden beast` number, since 7 + 81 + 2 + 2 + 1 + 13 + 0 + 560 = 666.

It is a super-3 number, since 3×781221130560³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 244818565 + ... + 244821755.

It is an arithmetic number, because the mean of its divisors is an integer number (5786451216).

Almost surely, 2^781221130560 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781221130560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1458185706432).

781221130560 is an abundant number, since it is smaller than the sum of its proper divisors (2135150282304).

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

781221130560 is a wasteful number, since it uses less digits than its factorization.

781221130560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3743 (or 3717 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 781221130560 in words is "seven hundred eighty-one billion, two hundred twenty-one million, one hundred thirty thousand, five hundred sixty".