781377283601640 has 1152 divisors, whose sum is σ = 2977832632320000. Its totient is φ = 177040428364800.

The previous prime is 781377283601633. The next prime is 781377283601641. The reversal of 781377283601640 is 46106382773187.

781377283601640 is a `hidden beast` number, since 7 + 8 + 13 + 7 + 7 + 2 + 8 + 3 + 601 + 6 + 4 + 0 = 666.

It is a super-2 number, since 2×781377283601640² (a number of 31 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781377283601641) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 95394609945 + ... + 95394618135.

It is an arithmetic number, because the mean of its divisors is an integer number (2584924160000).

Almost surely, 2^{781377283601640} 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 781377283601640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1488916316160000).

781377283601640 is an abundant number, since it is smaller than the sum of its proper divisors (2196455348718360).

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

781377283601640 is a wasteful number, since it uses less digits than its factorization.

781377283601640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9787 (or 9769 counting only the distinct ones).

The product of its (nonzero) digits is 56899584, while the sum is 63.

The spelling of 781377283601640 in words is "seven hundred eighty-one trillion, three hundred seventy-seven billion, two hundred eighty-three million, six hundred one thousand, six hundred forty".