78434979840 has 1248 divisors, whose sum is σ = 335620786176. Its totient is φ = 16562257920.

The previous prime is 78434979793. The next prime is 78434979851. The reversal of 78434979840 is 4897943487.

78434979840 is a `hidden beast` number, since 78 + 434 + 9 + 7 + 98 + 40 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1479905254 + ... + 1479905306.

It is an arithmetic number, because the mean of its divisors is an integer number (268926912).

Almost surely, 2^78434979840 is an apocalyptic number.

78434979840 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 78434979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167810393088).

78434979840 is an abundant number, since it is smaller than the sum of its proper divisors (257185806336).

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

78434979840 is a wasteful number, since it uses less digits than its factorization.

78434979840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 48771072, while the sum is 63.

The spelling of 78434979840 in words is "seventy-eight billion, four hundred thirty-four million, nine hundred seventy-nine thousand, eight hundred forty".