78105378816 has 384 divisors, whose sum is σ = 248184714960. Its totient is φ = 24461180928.

The previous prime is 78105378781. The next prime is 78105378817. The reversal of 78105378816 is 61887350187.

It is a happy number.

78105378816 is a `hidden beast` number, since 7 + 8 + 10 + 537 + 88 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×78105378816² (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 not an unprimeable number, because it can be changed into a prime (78105378817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135364320 + ... + 135364896.

Almost surely, 2^78105378816 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 78105378816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124092357480).

78105378816 is an abundant number, since it is smaller than the sum of its proper divisors (170079336144).

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

78105378816 is an frugal number, since it uses more digits than its factorization.

78105378816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639 (or 599 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 78105378816 in words is "seventy-eight billion, one hundred five million, three hundred seventy-eight thousand, eight hundred sixteen".