78406755840 has 800 divisors, whose sum is σ = 337957297920. Its totient is φ = 16972333056.

The previous prime is 78406755839. The next prime is 78406755857. The reversal of 78406755840 is 4855760487.

78406755840 is a `hidden beast` number, since 7 + 8 + 40 + 6 + 7 + 558 + 40 = 666.

It is a super-2 number, since 2×78406755840² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 27577459 + ... + 27580301.

Almost surely, 2^78406755840 is an apocalyptic number.

78406755840 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 78406755840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168978648960).

78406755840 is an abundant number, since it is smaller than the sum of its proper divisors (259550542080).

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

78406755840 is a wasteful number, since it uses less digits than its factorization.

78406755840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2904 (or 2879 counting only the distinct ones).

The product of its (nonzero) digits is 7526400, while the sum is 54.

The spelling of 78406755840 in words is "seventy-eight billion, four hundred six million, seven hundred fifty-five thousand, eight hundred forty".