78641781603840 has 3840 divisors, whose sum is σ = 367928035098624. Its totient is φ = 15651333734400.

The previous prime is 78641781603787. The next prime is 78641781603841. The reversal of 78641781603840 is 4830618714687.

78641781603840 is a `hidden beast` number, since 7 + 8 + 6 + 4 + 17 + 8 + 1 + 603 + 8 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78641781603841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 71950394334 + ... + 71950395426.

Almost surely, 2^{78641781603840} is an apocalyptic number.

78641781603840 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 78641781603840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183964017549312).

78641781603840 is an abundant number, since it is smaller than the sum of its proper divisors (289286253494784).

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

78641781603840 is a wasteful number, since it uses less digits than its factorization.

78641781603840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1223 (or 1195 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 63.

The spelling of 78641781603840 in words is "seventy-eight trillion, six hundred forty-one billion, seven hundred eighty-one million, six hundred three thousand, eight hundred forty".