78620779872 has 144 divisors (see below), whose sum is σ = 232277677632. Its totient is φ = 26159552640.

The previous prime is 78620779849. The next prime is 78620779879. The reversal of 78620779872 is 27897702687.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78620779879) 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, 4431243 + ... + 4448949.

It is an arithmetic number, because the mean of its divisors is an integer number (1613039428).

Almost surely, 2^78620779872 is an apocalyptic number.

78620779872 is a gapful number since it is divisible by the number (72) 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 78620779872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116138838816).

78620779872 is an abundant number, since it is smaller than the sum of its proper divisors (153656897760).

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

78620779872 is a wasteful number, since it uses less digits than its factorization.

78620779872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18303 (or 18283 counting only the distinct ones).

The product of its (nonzero) digits is 33191424, while the sum is 63.

The spelling of 78620779872 in words is "seventy-eight billion, six hundred twenty million, seven hundred seventy-nine thousand, eight hundred seventy-two".